DOCSLIB.ORG

Enzymatic Synthesis and Decarboxylation of Phosphatidylserine in Tetrahymena Pyrzformis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Enzymatic Synthesis and Decarboxylation of Phosphatidylserine in Tetrahymena Pyrzformis Enzymatic synthesis and decarboxylation of phosphatidylserine in Tetrahymena pyrzformis EDWARD A. DENNIS* and EUGENE P. KENNEDY Department of Biological Chemistry, Harvard Downloaded from Medical School, Boston, Massachusetts 021 15 www.jlr.org ABSTRACT Cell-free extracts of the protozoan Tetrahymena This is the only known pathway for serine incorporation pyriformis have been found to catalyze the following reactions: into phospholipid in animal tissues. Phosphatidylethanolamine L-Serine “, Phosphatidylserine In contrast, bacteria produce phosphatidylserine di- + at Univ of California - San Diego Serials/Biomed Lib 0699, on December 26, 2020 + Ethanolamine rectly from CDP-diglyceride and L-serine (4) : Phosphatidylserine Phosphatidylethanolamine + C02 - ~ ~~~ ~~ (3) CDP-diglyceride + L-Serine --t Phosphatidylserine Net: L-Serine + Ethanolamine + COZ + CMP The biosynthesis of phosphatidylserine in this organism In both animal and bacterial systems, the decarboxyla- resembles that found in higher animals. In contrast, phospha- tion (3, 5,6) of serine takes place at the lipid level: tidylserine is formed in bacteria in a reaction between CDP- is diglyceride and L-serine. A detailed description presented (4) Phosphatidylserine -P Phosphatidylethanolamine of the enzyme that catalyzes the synthesis of phosphatidylserine + c02 in Tetrahymena by the exchange reaction, together with some properties of the phosphatidylserine decarboxylase in this In animal tissues, reactions (2) and (4) comprise the organism. “decarboxylation cycle” discussed by Kennedy (2) and illustrated in Fig. 1. This cycle leads to the net produc- SUPPLEMENTARY KEY WORDS biosynthesis 1 ex- tion of ethanolamine and COZ. change enzyme . mechanism - phosphatidylethanolamine . Since these two distinct pathways exist for animal and phosphatidylserine decarboxylase phospholipids bacterial systems, it was of interest to determine the pathway in protozoa. In this paper, we shall present evidence for the occurrence of enzymes catalyzing re- actions (2) and (4) in the protozoan Tetrahymena Pyri- THEde novo formation of the phosphodiester bond of formis. Reaction (3) has not been detected in Tetra- phospholipids always involves cytidine coenzymes (1, 2). hymena, nor has it been demonstrated in any animal However, the pathway for the formation of serine- and tissue. The exchange enzyme catalyzing reaction (2) in ethanolamine-containing phospholipids differs in animal cell-free preparations of Tetrahymena will be described and bacterial systems. In animal tissues, CDP-ethanol- in some detail; this enzyme has similar properties to the amine is an obligatory intermediate in the formation of analogous enzyme found in rat liver (3,7) and the house- phosphatidylethanolamine via reaction (7) which leads fly, Musca domestica (8). to the net formation of the phosphodiester bond. This study of the pathway for phosphatidylserine and phosphatidylethanolamine biosynthesis in Tetrahymena (7) CDP-ethanolamine a,@-DiglyceridetPhosphati- + has one further purpose. Tetrahymena contains consider- dylethanolamine CMP + able amounts of the phosphono analogue of phos- The incorporation of serine into phospholipid in phatidylethanolamine. The natural occurrence of the animal tissues (3) takes place via an exchange reaction : * Postdoctoral Fellow of the U. S. Public Health Service, (2) Phosphatidylethanolamine + L-Serine Phosphati- National Institute of Arthritis and Metabolic Diseases, #5-F2- dylserine + Ethanolamine AM-20,008. 394 JOURNALOF LIPID RESEARCH VOLUME 11, 1970 magnetic stirrer and maintained at 28-30°C in a water bath or (6) 14 liters of medium (containing 0.5 ml of OH NH2 silicone antifoam) in a Microferm Laboratory Fermentor (New Brunswick Scientific Co., New Brunswick, N. J.), equipped with mechanical stirring at 125 rpm, aeration at 4 psi, and maintained at 29°C. In the latter case, 1 A liter of log-phase cells was used as innoculum, and the cultures were harvested in log phase (about 24 hr) as follows : the culture was cooled with a circulating ethylene FIG. 1. Decarboxylation cycle in animal tissues. glycol bath to about 2"C, and the cells were collected in a Sorvall centrifuge equipped with a Szent-Gyorgyi Blum continuous flow system (15,000 g, O"C, 150 ml/min flow Downloaded from phosphonolipids was first demonstrated by Horiguchi rate). The cells were washed once with 1.2 liter of buffer and Kandatsu in 1959 (9). Since then, the biochemistry containing 20 m~ imidazole-HC1, pH 7.1, 0.25 M sucrose, of these lipids in Tetrahymena, several marine inverte- and 5 m~ mercaptoethanol, and the cells were collected brates, and higher animals has been the object of con- by centrifugation (15,000 g, O°C, 15 min). siderable study (10, 11). The mechanism of the bio- The washed cells were taken up in 125 ml of the same www.jlr.org synthesis of the phosphonolipids has not yet been buffer and disrupted with a Potter-Elvejhem homog- elucidated. However, available evidence suggests that the enizer (60 strokes, O"C, 25-ml batches). Samples were synthesis of the C-P bond occurs at the lipid level (12-14). checked microscopically to insure complete cell breakage. at Univ of California - San Diego Serials/Biomed Lib 0699, on December 26, 2020 The pathways for the biosynthesis of the ethanolamine- The broken cells were centrifuged (10,000 g, O'C, 30 and serine-containing lipids in this organism are thus min), and the pellet was washed with 150 ml of buffer of special interest. Glu~ose-'~Cand related compounds and respun. The washed pellet was taken up in 30 ml of are the precursors of the polar head-groups of the phos- 0.25 M sucrose, frozen in methyl Cellosolve or dry ice, phonolipids (13, 15-17), and it has been suggested that and lyophilized. The resulting lyophilized powder was phosphoenolpyruvate or oxaloacetate may be inter- stored in the cold and retained full enzymatic activity mediates. Since it is possible that these compounds may for at least 6 months. A 14 liter preparation harvested be incorporated into phospholipids by way of an ex- in early log phase according to the above procedure change reaction, we have tested phosphoenolpyruvate usually yielded about 3.0 g of lyophilized powder con- and oxaloacetate for their ability to displace ethanol- taining about 0.5-0.8 g of protein (about 60% of the amine from labeled phosphatidylethanolamine in cell- protein in the unwashed homogenate) as determined by free extracts under conditions in which the exchange the method of Lowry, Rosebrough, Farr, and Randall enzyme is active. Neither compound appears to be a (18). About 90% of the enzymatic activity appeared in substrate for this enzyme. the 10,000 g pellet; the other 10% of the enzymatic activity could be recovered froin the pellet sedimenting MATERIALS AND METHODS between 10,000 g and 105,000 g. Culture Conditions Sucrose Density Gradient Centrifugation A culture of Tetrahymena pyriformis W (Strain 10542) was Early log-phase cultures were grown in 500-ml batches, obtained from the American Type Culture Collection harvested by centrifugation (15,000 g, O'C, 15 min), (Rockville, Md.). The growth medium consisted of washed with 0.2 M NaCl, disrupted with the Potter- 0.5% proteose peptone (Difco Inc., Findlay, Ohio), Elvejhem homogenizer in buffer (20 m~ imidazole- 0.5% bactotryptone (Difco Inc.), and 0.02% KHzPOd HCl, pH 7.1, 0.25 M sucrose), and centrifuged (lO,OOOg, (Mallinckrodt Chemical Works, St. Louis, Mo.). The O"C, 30 min). The pellet was taken up in a small amount pH was adjusted to 7.1 with KOH. Stock cultures were of the same buffer, and a sample (1 .O ml) was applied to grown at room temperature and were transferred weekly. a sucrose gradient which contained 20 mM imidazole- Cultures were examined periodically using a phase- HCl, pH 7.1, and consisted of a 0.5 nil cushion of d 1.32, contrast microscope; growth was monitored at 650 nm. and 3.6 ml of a linear gradient of d 1.14-1.27 in a cellu- Under these conditions, mid-exponential phase was lose nitrate tube of capacity 5.2 nil. The tube was centri- reached in 2-3 days. fuged in the SW 39 rotor of a Beckman Model L ultra- centrifuge (100,000 g, O"C, 150 min). After centrifuga- CeU-Free Extracts tion, the contents were collected in 3-drop samples Cultures were grown as above using either (a) 500 ml of (approximately 0.2 ml each) by puncturing the bottom medium in a 2 liter DeLong culture flask equipped with a of the tube. DENNISAND KENNEDY Enzymatic Synthesis, Decarboxylation of Phosphatidylserine 395 Assay of the Exchange Enzyme mg of protein per ml. The flask was stoppered with a rub- The following procedure (19, 20) was used for assay of ber serum cap and shaken by gentle rocking in a thermo- the exchange enzyme : assays were carried out in conical- statted water bath. Reactions were stopped with 0.5 tipped vessels (40 ml capacity) using a final incubation ml of 0.5 N H2S04 added by syringe through the cap volume of 0.4 ml. The standard assay system consisted of to the reaction mixture. Shaking was then continued for 50 m~ imidazole-HC1, final pH 7.7, 1.5 mM ~-serine-3- an additional 30 min. The KOH-impregnated paper 14C at lo6 cpm/pmole, and 20 m~ CaC12. Incubations was counted in 1 ml of water and 10 ml of 2 : 1 Patterson- were conducted at 22°C for 10 min. For “zero-time” Greene counting solution. As with the phospholipid controls, methanol was added at this point. The vessels assay, the average of duplicate determinations (SD *0.2 containing the assay reagents and radioactive label nmoles of 14C02)is reported, and zero-time values have were equilibrated in a water bath at the appropriate been subtracted. temperature; then cell-free preparations of Tetrahymena Downloaded from of (lyophilized powder resuspended in water and subjected Preparation Phosphatidylethanolamine-l,2-l4C to five strokes with the Potter-Elvejhem homogenizer) Phosphatidylethanolamine-1 ,2-14C was generated in situ were added to initiate the reaction.
Load more

Recommended publications
  • Decarboxylation What Is Decarboxylation?
    Decarboxylation What is decarboxylation? Decarboxylation is the removal of a carboxyl group when a compound is exposed to light or heat. A carboxyl group is a grouping of carbon, oxygen, and hydrogen atoms in the form of COOH. When a compound is decarboxylated, this group is released in the form of carbon dioxide. Decarboxylation of cannabinoids When considering the decarboxylation of cannabinoids, it is important to note that this reaction is what causes the neutral acidic cannabinoids to turn into the active cannabinoids found in most products on the market. Both the neutral and acidic cannabinoids are naturally found in the cannabis plant. The active cannabinoids that have psychoactive properties are what occur after decarboxylation. Below is the mechanism for the conversion of THCA to THC. https://www.leafscience.com/2017/04/13/what-is-thca/ Heating THCA converts it to THC by kicking off the carboxyl group seen on the right side of the THCA molecule. Once the carboxyl group is released from the THCA it forms carbon dioxide and the THC compound. The THC is now ready for use in different products and will provide the psychoactive effects that popularized this compound. This simple reaction is all it takes to convert the acidic cannabinoids to their active counterparts. Cannabinolic acid (CBDA) and CBD are both another example of this process. Decarboxylation process Light can start the decarboxylation process after a period of time, but heat is the more common element used. There are different methods to decarboxylate cannabis depending on user preference. In the industry, dabs, vapes and joints decarboxylate instantly when heat is applied to the product.
    [Show full text]
  • Optimization of the Decarboxylation Reaction in Cannabis
    APPLICATION NOTE FT-IR Spectroscopy Authors: Dr. Markus Roggen1 Antonio M. Marelli1 Doug Townsend2 Ariel Bohman2 1Outco SanDiego, CA 2PerkinElmer, Inc. Shelton, CT. Optimization of the Decarboxylation Reaction Introduction The production of cannabis in Cannabis Extract extracts and oils for medicinal and recreational products has increased significantly in North America. This growth has been driven by both market demand in newly legalized states and patient demand for a greater diversity in cannabis products.1,2,3 Most cannabis extraction processes, independent of solvent or instrument choice, undergo a decarboxylation step whereby the carboxylic acid functional group is removed from the cannabinoids. The decarboxylation reaction converts the naturally occurring acid forms of the cannabinoids, e.g. tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA), to their more potent neutral forms, e.g. tetrahydrocannabinol (THC) and cannabidiol (CBD). Because the carboxylic acid group is thermally labile, the industry typically applies a heat source, and at times a catalyst, to decarboxylate the cannabinoids. The heat-promoted decarboxylation reaction has been Decarboxylation Reaction discussed at length within the industry, but an extensive Decarboxylation was achieved by heating the cannabis extract in 4, 5, 6 literature search reveals very few papers on the process. a oil bath with a programmable hot plate. An overhead stirrer The data available represents a large spectrum of reaction was utilized to promote even heat distribution throughout the conditions, including a range in reaction temperature, time experiment. Oil bath and extract temperatures were recorded and instrumental setup. As such, there is a lack of universal every five minutes throughout the 80-minute heating process.
    [Show full text]
  • Citric Acid Cycle
    CHEM464 / Medh, J.D. The Citric Acid Cycle Citric Acid Cycle: Central Role in Catabolism • Stage II of catabolism involves the conversion of carbohydrates, fats and aminoacids into acetylCoA • In aerobic organisms, citric acid cycle makes up the final stage of catabolism when acetyl CoA is completely oxidized to CO2. • Also called Krebs cycle or tricarboxylic acid (TCA) cycle. • It is a central integrative pathway that harvests chemical energy from biological fuel in the form of electrons in NADH and FADH2 (oxidation is loss of electrons). • NADH and FADH2 transfer electrons via the electron transport chain to final electron acceptor, O2, to form H2O. Entry of Pyruvate into the TCA cycle • Pyruvate is formed in the cytosol as a product of glycolysis • For entry into the TCA cycle, it has to be converted to Acetyl CoA. • Oxidation of pyruvate to acetyl CoA is catalyzed by the pyruvate dehydrogenase complex in the mitochondria • Mitochondria consist of inner and outer membranes and the matrix • Enzymes of the PDH complex and the TCA cycle (except succinate dehydrogenase) are in the matrix • Pyruvate translocase is an antiporter present in the inner mitochondrial membrane that allows entry of a molecule of pyruvate in exchange for a hydroxide ion. 1 CHEM464 / Medh, J.D. The Citric Acid Cycle The Pyruvate Dehydrogenase (PDH) complex • The PDH complex consists of 3 enzymes. They are: pyruvate dehydrogenase (E1), Dihydrolipoyl transacetylase (E2) and dihydrolipoyl dehydrogenase (E3). • It has 5 cofactors: CoASH, NAD+, lipoamide, TPP and FAD. CoASH and NAD+ participate stoichiometrically in the reaction, the other 3 cofactors have catalytic functions.
    [Show full text]
  • Lecture: 28 TRANSAMINATION, DEAMINATION and DECARBOXYLATION
    Lecture: 28 TRANSAMINATION, DEAMINATION AND DECARBOXYLATION Protein metabolism is a key physiological process in all forms of life. Proteins are converted to amino acids and then catabolised. The complete hydrolysis of a polypeptide requires mixture of peptidases because individual peptidases do not cleave all peptide bonds. Both exopeptidases and endopeptidases are required for complete conversion of protein to amino acids. Amino acid metabolism The amino acids not only function as energy metabolites but also used as precursors of many physiologically important compounds such as heme, bioactive amines, small peptides, nucleotides and nucleotide coenzymes. In normal human beings about 90% of the energy requirement is met by oxidation of carbohydrates and fats. The remaining 10% comes from oxidation of the carbon skeleton of amino acids. Since the 20 common protein amino acids are distinctive in terms of their carbon skeletons, amino acids require unique degradative pathway. The degradation of the carbon skeletons of 20 amino acids converges to just seven metabolic intermediates namely. i. Pyruvate ii. Acetyl CoA iii. Acetoacetyl CoA iv. -Ketoglutarate v. Succinyl CoA vi. Fumarate vii. Oxaloacetate Pyruvate, -ketoglutarate, succinyl CoA, fumarate and oxaloacetate can serve as precursors for glucose synthesis through gluconeogenesis.Amino acids giving rise to these intermediates are termed as glucogenic. Those amino acids degraded to yield acetyl CoA or acetoacetate are termed ketogenic since these compounds are used to synthesize ketone bodies. Some amino acids are both glucogenic and ketogenic (For example, phenylalanine, tyrosine, tryptophan and threonine. Catabolism of amino acids The important reaction commonly employed in the breakdown of an amino acid is always the removal of its -amino group.
    [Show full text]
  • Dopa Decarboxylase Activity of the Living Human Brain
    Proc. Natl. Acad. Sci. USA Vol. 88, pp. 2721-2725, April 1991 Neurobiology Dopa decarboxylase activity of the living human brain (dopamine/dopamine synthesis/6-['8F]fluoro-L-dopa/Parkinson disease/positron emission tomography) ALBERT GJEDDE, JAKOB REITH, SUZAN DYVE, GABRIEL MGER, MARK GUTTMAN, MiRKo DIKSIC, ALAN EVANS, AND HIROTO KUWABARA Positron Imaging Laboratories, Montreal Neurological Institute, 3801 University Street, Montreal, Quebec H3A 2B4, Canada Communicated by Alfred P. Wolf, December 10, 1990 (received for review July 23, 1990) ABSTRACT Monoamiergic neurons use dopa decarbox- loss of methyl-Fdopa from the circulation, the methylation of ylase (DDC; aromatic-L-amino-acid carboxy-lyase, EC Fdopa in brain tissue, the exchange of Fdopa and methyl- 4.1.1.28) to form dopamine from L-3,4-dihydroxyphenylala- Fdopa between the circulation and brain tissue, and the nine (L-dopa). We measured regional dopa decarboxylase decarboxylation of Fdopa in the tissue. The model has too activity in brains of six healthy volunteers with 6-[18F]fluoro- many compartments to be evaluated by PET. We used known L-dopa and positron emission tomography. We calculated the relationships between the parameters to reduce the number enzyme activity, relative to its K., with a kinetic model that of compartments to three and the number of parameters to yielded the relative rate of conversion of 6['8Flfluoro-L-dopa four: We incorporated into each study (i) the ratio (0.43) to [18Fjfluorodopamine. Regional values of relative dopa de- between the blood-brain barrier transport rates ofFdopa and carboxylase activity ranged from nil in occipital cortex to 1.9 methyl-Fdopa in rat (5), (ii) the rate of conversion of Fdopa h-1 in caudate nucleus and putamen, in agreement with values to methyl-Fdopa and the rate of loss of methyl-Fdopa from obtained in vitro.
    [Show full text]
  • Therapeutic Effect of Agmatine on Neurological Disease: Focus on Ion Channels and Receptors
    Neurochemical Research (2019) 44:735–750 https://doi.org/10.1007/s11064-018-02712-1 REVIEW PAPER Therapeutic Effect of Agmatine on Neurological Disease: Focus on Ion Channels and Receptors Sumit Barua1 · Jong Youl Kim1 · Jae Young Kim1 · Jae Hwan Kim4 · Jong Eun Lee1,2,3 Received: 15 October 2018 / Revised: 19 December 2018 / Accepted: 24 December 2018 / Published online: 4 January 2019 © Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract The central nervous system (CNS) is the most injury-prone part of the mammalian body. Any acute or chronic, central or peripheral neurological disorder is related to abnormal biochemical and electrical signals in the brain cells. As a result, ion channels and receptors that are abundant in the nervous system and control the electrical and biochemical environment of the CNS play a vital role in neurological disease. The N-methyl-D-aspartate receptor, 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl) propanoic acid receptor, kainate receptor, acetylcholine receptor, serotonin receptor, α2-adrenoreceptor, and acid-sensing ion channels are among the major channels and receptors known to be key components of pathophysiological events in the CNS. The primary amine agmatine, a neuromodulator synthesized in the brain by decarboxylation of L-arginine, can regu- late ion channel cascades and receptors that are related to the major CNS disorders. In our previous studies, we established that agmatine was related to the regulation of cell differentiation, nitric oxide synthesis, and murine brain endothelial cell migration, relief of chronic pain, cerebral edema, and apoptotic cell death in experimental CNS disorders.
    [Show full text]
  • Pyruvate Dehydrogenase Complex Deficiency
    Pavlu‑Pereira et al. Orphanet J Rare Dis (2020) 15:298 https://doi.org/10.1186/s13023‑020‑01586‑3 RESEARCH Open Access Pyruvate dehydrogenase complex defciency: updating the clinical, metabolic and mutational landscapes in a cohort of Portuguese patients Hana Pavlu‑Pereira1, Maria João Silva1,2, Cristina Florindo1, Sílvia Sequeira3, Ana Cristina Ferreira3, Sofa Duarte3, Ana Luísa Rodrigues4, Patrícia Janeiro4, Anabela Oliveira5, Daniel Gomes5, Anabela Bandeira6, Esmeralda Martins6, Roseli Gomes7, Sérgia Soares7, Isabel Tavares de Almeida1,2, João B. Vicente8* and Isabel Rivera1,2* Abstract Background: The pyruvate dehydrogenase complex (PDC) catalyzes the irreversible decarboxylation of pyruvate into acetyl‑CoA. PDC defciency can be caused by alterations in any of the genes encoding its several subunits. The resulting phenotype, though very heterogeneous, mainly afects the central nervous system. The aim of this study is to describe and discuss the clinical, biochemical and genotypic information from thirteen PDC defcient patients, thus seeking to establish possible genotype–phenotype correlations. Results: The mutational spectrum showed that seven patients carry mutations in the PDHA1 gene encoding the E1α subunit, fve patients carry mutations in the PDHX gene encoding the E3 binding protein, and the remaining patient carries mutations in the DLD gene encoding the E3 subunit. These data corroborate earlier reports describing PDHA1 mutations as the predominant cause of PDC defciency but also reveal a notable prevalence of PDHX mutations among Portuguese patients, most of them carrying what seems to be a private mutation (p.R284X). The biochemical analyses revealed high lactate and pyruvate plasma levels whereas the lactate/pyruvate ratio was below 16; enzy‑ matic activities, when compared to control values, indicated to be independent from the genotype and ranged from 8.5% to 30%, the latter being considered a cut‑of value for primary PDC defciency.
    [Show full text]
  • Ontogeny of L-Glutamic Acid Decarboxylase and 7 -Aminobutyric Acid Concentration in Human Kidney
    Pediat. Res. 9: 484-487 (1975) a-Aminobutyric acid human kidney glutamic acid decarboxylase pyridoxal phosphate Ontogeny of L-Glutamic Acid Decarboxylase and 7 -Aminobutyric Acid Concentration in Human Kidney G. A. LANCASTER,'27' F. MOHYUDDIN, AND C. R. SCRIVER LIeBelle Laboratorv for Biochemical Genetics and the Medical Research Council Genetics Group. McGill University-Montreal Children's Hospital Research Institute, Montreal, Quebec. Canada Extract particular importance in man, who extracts glutamine from the plasma to generate ammonia in kidney (10). Under such condi- Mature human renal cortex contains y-aminobutyric acid tions, the net intrarenal burden of glutamate requiring disposal is (GABA) at concentrations on the order of 0.2 pnol/g wet wt and greater than in those species, such as the rat, in which intrarenal about half of that concentration in fetal kidney. glutamate is consumed to synthesize the glutamine used for The pyridoxal-5'-phosphate (PLP)-dependent enzyme, L- ammoniagenesis. Renal GABA is low in rat kidney relative to glutamic acid decarboxylase (GAD), catalyzes the conversion of human kidney (8), a finding we considered to be supportive of our L-glutamate to GABA. The PLP-saturated GAD activity in hypothesis concerning the role of the GABA pathway in kidney. post-term (1 day-9 years) renal cortex homogenate is 0.94 A 0.38 We have examined the ontogeny of L-glutamic acid decarboxyl- pnol CO, formed/g wet wt/hr (Table 1). The corresponding GAD ase, the initial enzyme committing glutamate to the GABA activity in fetal renal cortex, in the midtrimester and early third (P pathway.
    [Show full text]
  • Cooperative Interactions in Glutamic Acid Decarboxylase David Lavern Witte Iowa State University
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1971 Cooperative interactions in glutamic acid decarboxylase David Lavern Witte Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Biochemistry Commons Recommended Citation Witte, David Lavern, "Cooperative interactions in glutamic acid decarboxylase " (1971). Retrospective Theses and Dissertations. 4930. https://lib.dr.iastate.edu/rtd/4930 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. 71-26,904 WITTE, David Lavem, 1943- COOPERATIVE INTERACTIONS IN GLUTAMIC ACID DECARBOXYLASE. Iowa State University, Ph.D., 1971 Biochemistiy University Microfilms, A XEROX Company, Ann Arbor, Michigan THIS DISSERTATION HAS BEQf MICROFILMED EXACTLY AS RECEIVED Cooperative interactions in glutamic acid decarboxylase by David Lavern Witte A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Subject: Biochemistry Approved: Signature was redacted for privacy. Signature was redacted for privacy. H tment Signature was redacted for privacy. f Graduée College Iowa State University Of Science and Technology Ames, Iowa 1971 ii TABLE OF CONTENTS Page DEDICATION i i i ABBREVIATIONS iv INTRODUCTION 1 LITERATURE REVIEW 2 EXPERIMENTAL 15 RESULTS AND DISCUSSION 27 LITERATURE CITED 75 ACKNOWLEDGMENTS 78 APPENDIX 79 DEDICATION To iny wife iv ABBREVIATIONS ATCC - American Type Culture Collection CD - circular dichroistn DEAE - diethyl amino ethyl DTT - dithio threitol (CIel and's reagent) E.
    [Show full text]
  • The Involvement of Trace Amine-Associated Receptor 1 and Thyroid Hormone Transporters in Non-Classical Pathways of the Thyroid Gland Auto-Regulation
    The Involvement of Trace Amine-Associated Receptor 1 and Thyroid Hormone Transporters in Non-Classical Pathways of the Thyroid Gland Auto-Regulation by Maria Qatato a Thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Cell Biology Approved Dissertation Committee Prof. Dr. Klaudia Brix Jacobs University Bremen Prof. Sebastian Springer, DPhil Jacobs University Bremen Dr. Georg Homuth Ernst-Moritz-Arndt-Universität Greifswald Date of Defence: 16 January 2018 Department of Life Sciences and Chemistry Statutory Declaration Family Name, Given/First Name Qatato, Maria Matriculation number 20330110 What kind of thesis are you submitting: PhD Thesis English: Declaration of Authorship I hereby declare that the thesis submitted was created and written solely by myself without any external support. Any sources, direct or indirect, are marked as such. I am aware of the fact that the contents of the thesis in digital form may be revised with regard to usage of unauthorized aid as well as whether the whole or parts of it may be identified as plagiarism. I do agree my work to be entered into a database for it to be compared with existing sources, where it will remain in order to enable further comparisons with future theses. This does not grant any rights of reproduction and usage, however. This document was neither presented to any other examination board nor has it been published. German: Erklärung der Autorenschaft (Urheberschaft) Ich erkläre hiermit, dass die vorliegende Arbeit ohne fremde Hilfe ausschließlich von mir erstellt und geschrieben worden ist. Jedwede verwendeten Quellen, direkter oder indirekter Art, sind als solche kenntlich gemacht worden.
    [Show full text]
  • Role of Glycine and Glyoxylate Decarboxylation in Photorespiratory CO2 Release' Received for Publication February 5, 1981 and in Revised Form May 12, 1981
    Plant Physiol. (1981) 68,1031-1034 0032-0889/81/68/103 1/04/$00.50/0 Role of Glycine and Glyoxylate Decarboxylation in Photorespiratory CO2 Release' Received for publication February 5, 1981 and in revised form May 12, 1981 DAVID J. OLIVER Department ofBacteriology and Biochemistry, University ofIdaho, Moscow, Idaho 83843 ABSTRACT anism was shared with added glycine, was sensitive to INH2 (14) and KCN, and therefore involved the mitochondrial glycine de- Mechanicafly isolated soybean leafcells metabolized added glycolate by carboxylation reaction. The second mechanism of CO2 release two mechanisms, the direct oxidation ofglyoxylate and the decarboxylation from glycolate was insensitive to INH and KCN, not inhibited by of glycine. The rate of glyoxylate oxidation was dependent on the cellular added glycine, insensitive to glycidate, an inhibitor of the gluta- glyoxylate concentratn and was linear between 0.58 and 2.66 micromoles mate:glyoxylate amino transferase (9), and inhibited by the gly- glyoxylate per milligam chlorophyll Tbe rate extrapolated to zero at a colate oxidase inhibitor methylhydroxybutynoate (5). It appar- concentration of zero. The concentration and, therefore, the rate of oxi- ently resulted from the direct decarboxylation of glyoxylate. The dation of glyoxylate could be decreased by adding glutamate or serine to rates of CO2 release from these sites were approximately equal. the cells. These substrates were amino donors for the transamination of Recently, Somerville et al. (17) have shown that Arabidopsis glyoxylate to glycine. In the presence of these amino acids more CO1 was thaliana mutants with no measurable leaf mitochondrial serine released from added glycolate via the glycine decarboxylation reaction and hydroxymethyl transferase activity photorespire.
    [Show full text]
  • Tryptophan Catabolism by Lactobacillus Spp. : Biochemistry and Implications on Flavor Development in Reduced-Fat Cheddar Cheese
    Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 5-1998 Tryptophan Catabolism by Lactobacillus spp. : Biochemistry and Implications on Flavor Development in Reduced-Fat Cheddar Cheese Sanjay Gummalla Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Food Chemistry Commons, Food Microbiology Commons, and the Food Processing Commons Recommended Citation Gummalla, Sanjay, "Tryptophan Catabolism by Lactobacillus spp. : Biochemistry and Implications on Flavor Development in Reduced-Fat Cheddar Cheese" (1998). All Graduate Theses and Dissertations. 5454. https://digitalcommons.usu.edu/etd/5454 This Thesis is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. TRYPTOPHAN CATABOLISM BY LACTOBACILLUS SPP.: BIOCHEMISTRY AND IMPLICATIONS ON FLAVOR DEVELOPMENT IN REDUCED-FAT CHEDDAR CHEESE by Sanjay Gummalla A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE m Nutrition and Food Sciences Approved: UTAH STATE UNIVERSITY Logan, Utah 1998 11 Copyright © Sanjay Gummalla 1998 All Rights Reserved w ABSTRACT Tryptophan Catabolism by Lactobacillus spp. : Biochemistry and Implications on Flavor Development in Reduced-Fat Cheddar Cheese by Sanjay Gummalla, Master of Science Utah State University, 1998 Major Professor: Dr. Jeffery R. Broadbent Department: Nutrition and Food Sciences Amino acids derived from the degradation of casein in cheese serve as precursors for the generation of key flavor compounds. Microbial degradation of tryptophan (Trp) is thought to promote formation of aromatic compounds that impart putrid fecal or unclean flavors in cheese, but pathways for their production have not been established.
    [Show full text]