DOCSLIB.ORG

Milk Protein Digestion in Premature Infants: a Peptidomics and Enzyme Analysis Approach

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Milk Protein Digestion in Premature Infants: a Peptidomics and Enzyme Analysis Approach Milk Protein Digestion in Premature Infants: a Peptidomics and Enzyme Analysis Approach David Dallas Assistant Professor Nutrition Program School of Biological and Population Health Sciences www.dallaslab.org Milk proteins Wesley, 2008 Infant digestion peptidase (Stevens, 2010, Epithelial Transport Physiology) Isolated Antimicrobial enzyme Anti- hypertensive In vitro digestion Calcium-binding Immune modulation Opioid Isolated milk protein Premature infant digestive system • produce less gastric acid • lower gastric pepsin and intestinal protease activity than in term infants Preterm Term Adult Pepsin activity1 (U/mL) 12 125 (10X) 600 (50X) Gastric pH 2 4.1 – 5.8 3.2 – 5.0 1.8 – 2.0 Elastase level3 (µg/g) 113 – 127 129 – 160 > 200 Adapted from Henderson et al. (2001)1, Armand et al. (1995, 1996)1, Mason (1962)2, Kori et al. (2016)3. • Lack of digestive capacity: critical • Digestion of milk proteins = peptides with antimicrobial and immunological activities Collect Folch Precipitate Centrifuge skim protein lipid 10-50 µL milk supernatant C18 solid phase extraction Dry down and Inject rehydrate Isolation, fragmentation and detection Collision Fragment Neutral Collision gas ion loss cell Precursor Fragment ions ions (product ions) Activated Fragmenting Activated fragment ion ion ion (continues to fragment) Tandem spectra can be annotated manually. AVADTRDQADGSRASVDSGSSEEQGGSSRA from polymeric immunoglobulin receptor GGSSRA AVADTRDQADGSRASVDSGSSE 1081.981 AVADTRDQADGSRASVDSGSS 1017.460 AVADTRDQADGSRASVDSGS 973.944 AVADTRDQADGSRASVDSG 930.428 QGGSSRA AVADTRDQADGSRASVD 858.401 SRA -Q AV 333.188 GSSRA 171.113 SSRA -G -G -S Does milk contain peptides? • Assumption: Only intact proteins • Findings: – Yes, approximately 300 peptides present • Our new research shows 1-2 thousand – Mostly the same peptides for all healthy mothers (Dallas et al., 2013. J. Proteome Research. “Extensive in vivo milk peptidomics reveals specific proteolysis yielding protective antimicrobial peptides”) Which enzymes cleave the proteins? Milk contains complex system of proteases and antiproteases Type 1 plasminogen activator inhibitor α-2 antiplasmin Prothrombin Plasminogen X u-PA t-PA Thrombin X Trypsinogen Plasmin X Antithrombin III Prekallikrein Thrombin inhibitor X Proelastase Trypsin Kallikrein Inter-α-trypsin inhibitor Elastase X α-1-antitrypsin X X SERPINA5 Kallistatin X SERPING1 Procathepsin D Anti-elastase X α-1-antichymotrypsin X Cathepsin D Dallas et al. (2015) Bioinformatic Approach Active Enzymes: • Map cleavage sites -plasmin • Compare to enzyme -elastase specificity tables -cathepsin D -carboxypeptidase B (Khaldi, Dallas et al., JAFC) Protease activity by fluorometric or spectrometric assays A) Add supernatant human milk or preterm samples to tube D) Read with a microplate reader gastric samples (2X) Add standards and blanks in other tubes B) Add buffer and synthetic substrate* and incubate at 37°C C) Transfer in a microplate Centrifuge at 3,000 for 60 min rpm, 10 min at 4°C Activity was determined for: 300000 • Total protease 250000 • Plasmin 200000 • Elastase 150000 • Kallikrein 100000 y = 2568.5x - 2287 R² = 0.99914 • Thrombin (485/535nm) 50000 0 • Cathepsin D Valuefluorescence RFU 0 20 40 60 80 100 Fluorophore • Carboxypeptidase Standard protease (ng/mL) Many proteases not only present, but active in human milk! • Identified proteases • By abundance (high to low) • By activity (high to low) – Carboxypeptidase B2 – Kallikrein – Plasmin – Carboxypeptidase – Kallikrein – Cathepsin D – Elastase – Plasmin – Thrombin – Thrombin – Cathepsin D – Elastase – Cytosol aminopeptidase – Cytosol aminopeptidase Veronique Demers-Mathieu et al., submitted to Journal of Nutrition Demers-Mathieu Human milk protease inhibitors found • By abundance (high to low) – α1-antitrypsin – Antithrombin III – α1-antichymotrypsin – α2-antiplasmin – plasma serine protease inhibitor Is mammary gland digestion protein-selective? Results Common name Number of Not digested: peptides β–casein 316 - Lactoferrin Polymeric immunoglobulin receptor 54 - α-lactalbumin Osteopontin 41 Butyrophilin 27 - Immunoglobulins α s1-casein 25 Mucin 1 9 Peptide release is selective! κ-casein 8 Perilpin-2 5 Bile salt-activated lipase 2 Lactoperoxidase 2 Macrophage mannose receptor 2 Misshapen-like kinase 1 2 Sialic acid binding Ig-like lectin 9 2 Proteins with only 1 unique peptide 13 (Dallas et al., 2013. J. Proteome Research) What functions do the peptides have? Building a functional milk peptide database Initiated at UC Davis (200 peptides) Functional milk peptide database Expanded and improved at OSU: Milk Bioactive Peptide Database MBPDB (892 peptides) • 2,801 articles mined -> 254 with unique original identifications • Carefully referenced • Publishing public database Soeren Drud Nielsen Rob Beverly Yuki Qu Online tool for peptide functional searching • Many ways to search (identical, truncated, precursor and homology) • Batch search (multiple sequences) • Many additional search options (e.g. function, category, species, protein). Functional milk peptide database • Antihypertensive • Antimicrobial • Antioxidant • Anti-inflammatory • Opioid • Etc. • Across all available milk species, includes bovine, human, goat, sheep, camel, pig, etc. Mapping function, frequency and activity Homology search Homology search Antimicrobial peptide Functional prediction Soeren Drud Nielsen Predicting functional peptides across the protein sequence Are peptides different between term and preterm milk over lactation? Peptide Count • Effect of lactation stage: not significant • Effect of maturation: significant <0.001) 450 Preterm *** *** Term 400 ** 350 300 250 200 150 100 50 0 Number of peptides <14 14-28 29-41 42-58 Lactation period Peptides identified by protein 200 *** Preterm Term 180 160 140 120 100 80 *** *** ** 60 *** 40 Number of peptides 20 0 CASB OSTP CASA1 PIGR Other • CASB = β-casein • OSTP = osteopontin • CASA1 = αs1-casein • PIGR = polymeric immunoglobulin receptor Enzyme Activity 2.0x108 2.0E+08 Preterm * Term 8 1.6x101.6E+08 1.2x101.2E+088 8.0x108.0E+077 *** 4.0x104.0E+077 Enzyme activity (ion counts) Enzyme activity(ion 0.0E+000.0 Plasmin/trypsin Carboxypeptidase Cytosol Cathepsin D Elastase B2 aminopeptidase Enzyme Specificity of enzymes in protein digestion Abundance (ion counts) 1.50E+07 2.00E+07 2.50E+07 0.00E+00 5.00E+06 1.00E+07 N - terminus 1 6 11 16 21 26 α 31 s1 36 - 41 casein 46 51 56 61 66 amino 71 76 81 86 91 acid 96 101 106 Standard error:term Term Standard error:preterm Preterm position 111 116 121 126 131 136 141 146 151 C 156 - terminus 161 166 171 176 181 Summary • Greater abundance of peptides and enzyme activity in pre-term milk • Preterm infants are receiving substantially different milk! Among mother’s of preterm infants, do their milk proteases differ with length of gestation or infant day of life? Few differences in proteases in preterm mother’s milk across gestational age at delivery and time post partum • Groups – Early gestational age (24-26 weeks) – Late gestational age (27-32) • Mostly stayed constant! How much digestion occurs in the infant? What peptides are released? Results intact gastric (Dallas et al., 2014, JN, accepted. “A peptidomic analysis of human milk digestion in the infant stomach reveals protein-specific degradation patterns”) Results: peptides increase over 2-fold from intact to gastric sample 500 P-value: 1.29E-06 450 400 350 300 250 200 150 Number of peptides found 100 50 0 milk gastric Digestion is occurring despite high pH and low predicted pepsin activity Results 250 ** 60 50 ** 200 40 150 milk 30 100 gastric 20 ** ** 50 10 Number of peptides ** * ** * 0 0 Protein (Dallas et al., 2014, JN, accepted) Do preterm infants digest bovine and human milk proteins differently? • Preterm infants fed human milk enriched with human milk fortifier based on cow milk. • Highly similar amount of peptides released Human milk proteins Bovine milk proteins Protein sequence Species Function Mil Gastric Re k f αs1-CN FFVAPFPEVFGK Bovine ACE-inhibitory x x 100% matches αs1-CN IGSENSEKTTMP Bovine ACE-inhibitory x αs1-CN LRLKKYKVPQL Bovine Antimicrobial x x Are bioactive peptides αs1-CN RPKHPIKHQ Bovine ACE-inhibitory x x αs1-CN RPKHPIKHQGLPQEVLNENLLRF Bovine Antimicrobial x αs1-CN SDIPNPIGSENSEK Bovine Antimicrobial x x αs1-CN VLNENLLR Bovine Antimicrobial x released? αs1-CN YLGYLEQLLR Bovine Anxiolytic x x αs2-CN ALNEINQFYQK Bovine ACE-inhibitory x αs2-CN ALPQYLKTVYQHQKAMKPWIQPKTKVIPYV Bovine Antimicrobial x RYL αs2-CN AMKPWIQPK Bovine ACE-inhibitory x x αs2-CN FALPQYLK Bovine ACE-inhibitory x αs2-CN KTVYQHQKAMKPWIQPKTKVIPYVRYL Bovine Antimicrobial x αs2-CN LKKISQRYQKFALPQY Bovine Antimicrobial x αs2-CN TKVIPYVRYL Bovine Antimicrobial x αs2-CN VYQHQKAMKPWIQPKTKVIPYVRYL Bovine Antimicrobial x αs2-CN VYQHQKAMKPWIQPKTKVIPYVRYL Bovine Antimicrobial x αs2-CN YQKFPQY Bovine Antioxidant x x αs2-CN LKTVYQHQKAMKPWIQPKTKVIPYVRYL Bovine Antimicrobial x β-CN ENLHLPLPLL Human ACE-inhibitory x β-CN EPVLGPVRGPFP Bovine ACE-inhibitory x β-CN GVSKVKEAMAPKHKEMPFPKYPVEPFTESQ Bovine protective effects in x Using the similarity search function with a 90% enteritis β-CN HKEMPFPK Bovine Antimicrobial x x similarity threshold: β-CN LENLHLPLP Human ACE-inhibitory x β-CN MPFPKYPVEP Bovine ACE-inhibitory x β-CN PVVVPPFLQPE Bovine Antimicrobial x β-CN QEPVLGPVRGPFPIIV Bovine ACE-inhibitory x 277 β-CN RELEELNVPGEIVESLSSSEESITR Bovine CPP x β-CN VENLHLPLPLL Bovine ACE-inhibitory x bioactive peptides β-CN VKEAMAPK Bovine Antioxidant x x β-CN VLPVPQKAVPYPQR Bovine Antimicrobial x identified in
Load more

Recommended publications
  • University Microfilms International 300 N
    INFORMATION TO USERS This was produced from a copy of a document sent to us for microfilming. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help you understand markings or notations which may appear on this reproduction. 1. The sign or "target” for pages apparently lacking from the document photographed is "Missing Page(s)”. If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure you of complete continuity. 2. When an image on the film is obliterated with a round black mark it is an indication that the film inspector noticed either blurred copy because of movement during exposure, or duplicate copy. Unless we meant to delete copyrighted materials that should not have been filmed, you will find a good image of the page in the adjacent frame. If copyrighted materials were deleted you will find a target note listing the pages in the adjacent frame. 3. When a map, drawing or chart, etc., is part of the material being photo­ graphed the photographer has followed a definite method in “sectioning” the material. It is customary to begin filming at the upper left hand corner of a large sheet and to continue from left to right in equal sections with small overlaps. If necessary, sectioning is continued again—beginning below the first row and continuing on until complete.
    [Show full text]
  • An Interactomics Overview of the Human and Bovine Milk Proteome Over Lactation Lina Zhang1, Aalt D
    Zhang et al. Proteome Science (2017) 15:1 DOI 10.1186/s12953-016-0110-0 RESEARCH Open Access An interactomics overview of the human and bovine milk proteome over lactation Lina Zhang1, Aalt D. J. van Dijk2,3,4 and Kasper Hettinga1* Abstract Background: Milk is the most important food for growth and development of the neonate, because of its nutrient composition and presence of many bioactive proteins. Differences between human and bovine milk in low abundant proteins have not been extensively studied. To better understand the differences between human and bovine milk, the qualitative and quantitative differences in the milk proteome as well as their changes over lactation were compared using both label-free and labelled proteomics techniques. These datasets were analysed and compared, to better understand the role of milk proteins in development of the newborn. Methods: Human and bovine milk samples were prepared by using filter-aided sample preparation (FASP) combined with dimethyl labelling and analysed by nano LC LTQ-Orbitrap XL mass spectrometry. Results: The human and bovine milk proteome show similarities with regard to the distribution over biological functions, especially the dominant presence of enzymes, transport and immune-related proteins. At a quantitative level, the human and bovine milk proteome differed not only between species but also over lactation within species. Dominant enzymes that differed between species were those assisting in nutrient digestion, with bile salt- activated lipase being abundant in human milk and pancreatic ribonuclease being abundant in bovine milk. As lactation advances, immune-related proteins decreased slower in human milk compared to bovine milk.
    [Show full text]
  • Milk Allergen by the Numbers
    Milk allergen component testing Bos d4 Milk Bos allergen d5 Bos by the d8 numbers Detect sensitizations to the complete milk protein to create personalized management plans for your patients. High levels of milk IgE may predict the likelihood of sensitivity, but may not be solely predictive of TC 2851 reactions to baked milk or α-lactalbumin allergy duration.1 • Susceptible to heat denaturation2 • HIGHER RISK of reaction to fresh milk1,3 • LOWER RISK of reaction Milk allergen to baked milk1,3,a • Patient likely to “outgrow” component testing milk allergy4 Measurement of specific IgE by blood test that provides objective assessment of sensitization to milk is the first step in discovering your patient’s allergy. Milk allergen component tests can help α-lactalbumin β-lactoglobulin Casein Test interpretations and next steps you determine the likelihood of reaction to baked goods, such as cookies or cheese pizza, as well as • Avoid fresh milk the likelihood of allergy persistence. + + - • Likely to tolerate baked milk products • Baked milk oral food challenge (OFC), Knowing which protein your patient is with a specialist may be appropriate sensitized to can help you develop a + - - • Likely to outgrow allergy management plan.3,5-9 - + - • Avoid all forms of milk +/- +/- + • Unlikely to become tolerant of milk over time • Avoid milk and baked milk products (yogurt, cookies, cakes), as well as products processed with milk (chocolate, sausage, potato chips) % of children with milk allergy 75 do not react to baked milk.3 Bos d4 Bos Bos d5 d8 TC 2852 TC 2853 β-lactoglobulin Casein Determine • Susceptible to heat • Resistant to heat which proteins denaturation2 denaturation3 your patient is • HIGHER RISK of reaction • HIGHER RISK of reaction to fresh milk1,3 to all forms of milk1,3,5 sensitized to.
    [Show full text]
  • Protease-Activated Alpha-2-Macroglobulin Can Inhibit Amyloid Formation Via Two Distinct Mechanisms
    University of Wollongong Research Online Faculty of Science, Medicine and Health - Papers: part A Faculty of Science, Medicine and Health 1-1-2013 Protease-activated alpha-2-macroglobulin can inhibit amyloid formation via two distinct mechanisms Amy R. Wyatt University of Wollongong, [email protected] Patrick Constantinescu University of Wollongong, [email protected] Heath Ecroyd University of Wollongong, [email protected] Christopher M. Dobson University of Cambridge Mark R. Wilson University of Wollongong, [email protected] See next page for additional authors Follow this and additional works at: https://ro.uow.edu.au/smhpapers Part of the Medicine and Health Sciences Commons, and the Social and Behavioral Sciences Commons Recommended Citation Wyatt, Amy R.; Constantinescu, Patrick; Ecroyd, Heath; Dobson, Christopher M.; Wilson, Mark R.; Kumita, Janet R.; and Yerbury, Justin J., "Protease-activated alpha-2-macroglobulin can inhibit amyloid formation via two distinct mechanisms" (2013). Faculty of Science, Medicine and Health - Papers: part A. 745. https://ro.uow.edu.au/smhpapers/745 Research Online is the open access institutional repository for the University of Wollongong. For further information contact the UOW Library: [email protected] Protease-activated alpha-2-macroglobulin can inhibit amyloid formation via two distinct mechanisms Abstract α2-Macroglobulin (α2M) is an extracellular chaperone that inhibits amorphous and fibrillar protein aggregation. The reaction of α2M with proteases results in an ‘activated’ conformation, where the proteases become covalently-linked within the interior of a cage-like structure formed by α2M. This study investigates, the effect of activation on the ability of α2M to inhibit amyloid formation by Aβ1–42 and I59T human lysozyme and shows that protease-activated α2M can act via two distinct mechanisms: (i) by trapping proteases that remain able to degrade polypeptide chains and (ii) by a chaperone action that prevents misfolded clients from continuing along the amyloid forming pathway.
    [Show full text]
  • View a Sample of the Test Results (List of Allergens Tested)
    SAMPLE INFORMATION PATIENT INFORMATION Sample ID: Patient ID: Sampling date: 02.02.2021 Name: Approval status: Approved Birth date: Age: 32 Print date: 02.02.2021 ID/MR#: Gender: F Calibration curve: ORDERING PHYSICIAN INFORMATION Ordering physician: Address: London Allergy & Immunology Centre Ltd 1. Summary of positive IgE results Mainly species-specific aeroallergen components Grass pollen Bermuda grass Cyn d 1 Grass group 1 3,9 ISU-E Timothy grass Phl p 1 Grass group 1 13 ISU-E Phl p 4 Berberine bridge enzyme 2,5 ISU-E Phl p 5 Grass group 5 2,6 ISU-E Phl p 6 Grass group 6 0,6 ISU-E Tree pollen Birch Bet v 1 PR-10 protein 11 ISU-E Olive pollen Ole e 1 Common olive group 1 1,3 ISU-E Ole e 9 Beta-1,3-glucanase 0,8 ISU-E Animal Dog Can f 1 Lipocalin 13 ISU-E Can f 2 Lipocalin 6,5 ISU-E Can f 5 Arginine Esterase 26 ISU-E Can f 6 Lipocalin 1,7 ISU-E Horse Equ c 1 Lipocalin 3,6 ISU-E Cat Fel d 1 Uteroglobin 7,8 ISU-E Fel d 4 Lipocalin 0,6 ISU-E Mite D. farinae (HDM) Der f 2 NPC2 family 3,8 ISU-E D. pteronyssinus (HDM) Der p 2 NPC2 family 2,1 ISU-E SAMPLE ID: PATIENT ID: PATIENT NAME: 02.02.2021 Page 1 / 9 Cross-reactive components PR-10 protein Birch Bet v 1 PR-10 protein 11 ISU-E Alder Aln g 1 PR-10 protein 1,3 ISU-E Hazelnut Cor a 1.0401 PR-10 protein 1,9 ISU-E Apple Mal d 1 PR-10 protein 2,5 ISU-E Kiwi Act d 8 PR-10 protein 2,2 ISU-E ISAC Standardized Units (ISU-E) Level < 0.3 Undetectable 0.3 - 0.9 Low 1 - 14.9 Moderate / High Very High SAMPLE ID: PATIENT ID: PATIENT NAME: 02.02.2021 Page 2 / 9 SAMPLE INFORMATION PATIENT INFORMATION Sample ID: Patient ID: Sampling date: 02.02.2021 Name: Approval status: Approved Birth date: Age: 32 Print date: 02.02.2021 ID/MR#: Gender: F Calibration curve: ORDERING PHYSICIAN INFORMATION Ordering physician: Address: London Allergy & Immunology Centre Ltd 2.
    [Show full text]
  • ALEX® Allergen List (Extracts and Components)
    ALEX® allergen list (extracts and components) POLLEN w211 Wall pellitory rPar j 2 nsLTP 6 w10 White goosefoot TREE POLLEN w100 White goosefoot rChe a 1 Ole e 1-family 2 Code Allergen Source Component Protein Name t19 Acacia MOULD AND YEAST FUNGI t100 Alder Aln g 1 PR-10 protein 1 m229 Alternaria alternata rAlt a 1 Alt a 1-family t101 Alder Aln g 4 Polcalcin 4 t226 Arizona cypress nCup a 1 Pectate lyase 5 m230 Alternaria alternata rAlt a 6 Enolase t25 Ash m218 Aspergillus fumigatus rAsp f 1 Mitogillin Family 2 Peroxysomales t103 Ash rFra e 1 Ole e 1-family m220 Aspergillus fumigatus rAsp f 3 t300 Beech rFag s 1 PR-10 protein 1 protein t215 Birch rBet v 1 PR-10 protein 1 m221 Aspergillus fumigatus rAsp f 4 unknown Mn superoxide t216 Birch rBet v 2 Profilin m222 Aspergillus fumigatus rAsp f 6 t225 Birch rBet v 6 Isoflavon dismutase m2 Cladosporium her- reductase t222 Cypress barum t105 Date tree nPho d 2 Profilin 3 m100 Cladosporium her- rCla h 8 Short-chain dehy- t8 Elm barum drogenase y2 Malassezia sympo- rMala s 5 unknown t4 Hazel t102 Hazel rCor a 1.0103 PR-10 protein 1 dialis t303 Sugi rCry j 1 Pectate Lyase y3 Malassezia sympo- rMala s 6 Cyclophilin t6 Mountain ceder dialis t71 Mulberry y5 Malassezia sympo- rMala s 11 Mn superoxide t224 Olive nOle e 1 Ole e 1-family 2 dialis dismutase t240 Olive rOle e 9 1,3 β Glucanase m1 Penicilium chrysoge- t305 Paper mulberry num t241 Plane tree rPla a 1 Plant invertase MITES AND COCKROACHES t301 Plane tree nPla a 2 Polygalacturonase d70 Acarus siro t302 Plane tree rPla a 3 nsLTP 6 i100 Blatella
    [Show full text]
  • A Pea (Pisum Sativum L.) Seed Vicilins Hydrolysate Exhibits Pparγ Ligand Activity and Modulates Adipocyte Differentiation in a 3T3-L1 Cell Culture Model
    foods Article A Pea (Pisum sativum L.) Seed Vicilins Hydrolysate Exhibits PPARγ Ligand Activity and Modulates Adipocyte Differentiation in a 3T3-L1 Cell Culture Model Raquel Ruiz, Raquel Olías, Alfonso Clemente and Luis A. Rubio * Physiology and Biochemistry of Animal Nutrition, Estación Experimental del Zaidín (EEZ, CSIC), 18008 Granada, Spain; [email protected] (R.R.); [email protected] (R.O.); [email protected] (A.C.) * Correspondence: [email protected]; Tel.: +34-9585-7275-7; Fax: +34-9585-7275-3 Received: 19 May 2020; Accepted: 10 June 2020; Published: 16 June 2020 Abstract: Legume consumption has been reported to induce beneficial effects on obesity-associated metabolic disorders, but the underlying mechanisms have not been fully clarified. In the current work, pea (Pisum sativum L.) seed meal proteins (albumins, legumins and vicilins) were isolated, submitted to a simulated gastrointestinal digestion, and the effects of their hydrolysates (pea albumins hydrolysates (PAH), pea legumins hydrolysates (PLH) and pea vicilin hydrolysates (PVH), respectively) on 3T3-L1 murine pre-adipocytes were investigated. The pea vicilin hydrolysate (PVH), but not native pea vicilins, increased lipid accumulation during adipocyte differentiation. PVH also increased the mRNA expression levels of the adipocyte fatty acid-binding protein (aP2) and decreased that of pre-adipocyte factor-1 (Pref-1) (a pre-adipocyte marker gene), suggesting that PVH promotes adipocyte differentiation. Moreover, PVH induced adiponectin and insulin-responsive glucose transporter 4 (GLUT4) and stimulated glucose uptake. The expression levels of peroxisome proliferator-activated receptor γ (PPARγ), a key regulator of adipocyte differentiation, were up-regulated in 3T3-L1 cells treated with PVH during adipocyte differentiation.
    [Show full text]
  • Protease‐Activated Alpha‐2‐Macroglobulin Can Inhibit Amyloid
    FEBS Letters 587 (2013) 398–403 journal homepage: www.FEBSLetters.org Protease-activated alpha-2-macroglobulin can inhibit amyloid formation via two distinct mechanisms Amy R. Wyatt a,b, Patrick Constantinescu a, Heath Ecroyd a, Christopher M. Dobson b, Mark R. Wilson a, ⇑ ⇑ Janet R. Kumita b, , Justin J. Yerbury a, a Illawarra Health & Medical Research Institute, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia b Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK article info abstract Article history: a2-Macroglobulin (a2M) is an extracellular chaperone that inhibits amorphous and fibrillar protein Received 19 December 2012 aggregation. The reaction of a2M with proteases results in an ‘activated’ conformation, where the Accepted 4 January 2013 proteases become covalently-linked within the interior of a cage-like structure formed by a2M. This Available online 23 January 2013 study investigates, the effect of activation on the ability of a2M to inhibit amyloid formation by Ab and I59T human lysozyme and shows that protease-activated M can act via two distinct Edited by Noboru Mizushima 1–42 a2 mechanisms: (i) by trapping proteases that remain able to degrade polypeptide chains and (ii) by a chaperone action that prevents misfolded clients from continuing along the amyloid forming Keywords: pathway. a2-Macroglobulin Extracellular chaperone Amyloid disease Structured summary of protein interactions: Human lysozyme Ab1–42 and Ab1–42 bind by fluorescence technology (View interaction) Ab1–42 I59T lysozyme and I59T lysozyme bind by light scattering (View interaction) I59T lysozyme and I59T lysozyme bind by fluorescence technology (View interaction) Alpha-lactalbumin and Alpha-lactalbumin bind by fluorescence technology (View interaction) I59T lysozyme and I59T lysozyme bind by electron microscopy (View interaction) Ab1–42 and Ab1–42 bind by electron microscopy (View interaction) Ó 2013 Federation of European Biochemical Societies.
    [Show full text]
  • Human Milk Infographic
    © Human Milk 2017 Nucleotides are the basic building blocks of DNA and RNA. They can also form circular Amino acids are building blocks of proteins. Levels of free amino acids drop over time in human milk, but levels structures involved in cell signalling - activating or inhibiting processes within cells. of glutamic acid and glutamate (the highest percentage of free amino acids) increases. Significantly higher numbers of FAAs in human milk than cow’s milk. Leucine - Essential amino acid, important for Uridine the development of skeletal muscle. diphosphate-N-acetylhex- Helps to initiate the production of osamine (UDPAH) - proteins. The full functions of leucine are Cytidine diphosphate unknown, but may affect the rate of choline (CDP choline) - Important for the production of essential sugars required protein production and consequently the It appears to play a speed of growth of the baby. protective role against for normal growth and development. hypoxic brain damage, and Taurine - Essential for helps to improve memory brain and nervous system and learning. development. Helps to make membranes around and inside the cells and speeds up how quickly nerve signals can AaBbCc be transmitted. Fats in general have a number of functions ax2 + bx + c = 2 including: energy storage, cell messaging, hormone production and structural roles. Choline - Essential Proteins make up mineral for brain and Plasmalogens - Important approximately 16 - 20% nervous system development. es components of the immune, otid of the human body. Helps membrane to form cle nervous and cardiovascular around cells and nerve u systems. Plays a role in myelination N ) A Arachidonic acid (AHA) - signals to be m i of nerve fibres (laying down A fatty acid involved in transmitted quickly.
    [Show full text]
  • Lactoglobulin
    foods Review Milk Processing Affects Structure, Bioavailability and Immunogenicity of β-lactoglobulin Kerensa Broersen Department of Applied Stem Cell Technologies, TechMed Centre, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands; [email protected] Received: 10 June 2020; Accepted: 26 June 2020; Published: 3 July 2020 Abstract: Bovine milk is subjected to various processing steps to warrant constant quality and consumer safety. One of these steps is pasteurization, which involves the exposure of liquid milk to a high temperature for a limited amount of time. While such heating effectively ameliorates consumer safety concerns mediated by pathogenic bacteria, these conditions also have an impact on one of the main nutritional whey constituents of milk, the protein β-lactoglobulin. As a function of heating, β-lactoglobulin was shown to become increasingly prone to denaturation, aggregation, and lactose conjugation. This review discusses the implications of such heat-induced modifications on digestion and adsorption in the gastro-intestinal tract, and the responses these conformations elicit from the gastro-intestinal immune system. Keywords: bovine milk; pasteurization; β-lactoglobulin; digestion; aggregation; lactosylation; gastro-intestinal immune system 1. Introduction Milk of bovine origin is widely consumed at a global level. While bovine milk is a protein-rich beverage containing 30–36 g of total protein per liter, the precise composition of milk varies with animal breed, stage of lactation, age, and diet (reviewed in [1]). The most prominent proteins present in milk are the caseins consisting of α-s1, α-s2, and β and κ-caseins, and the whey proteins α-lactalbumin and β-lactoglobulin.
    [Show full text]
  • Structural and Biochemical Investigations of the Mechanism Of
    STRUCTURAL AND BIOCHEMICAL INVESTIGATIONS OF THE MECHANISM OF HEME CAPTURE BY THE HEMOPHORE HasAp SECRETED BY PSEUDOMONAS AERUGINOSA BY GRACE JEPKORIR LAGAT B.Ed. (Sci.), Kenyatta University, 1999 Nairobi, Kenya M.Ed. (Adm.), University of Eastern Africa, Baraton, 2002 Eldoret, Kenya Submitted to the graduate degree program in Chemistry and the Graduate Faculty of the University of Kansas in partial fulfillment of the requirements for the degree of Doctor of Philosophy Committee members: ___________________________ Mario Rivera, Ph. D. (Chair) ___________________________ Robert C. Dunn, Ph. D. ___________________________ Susan Lunte, Ph. D. ___________________________ Mikhail Barybin, Ph. D. ___________________________ Minae Mure, Ph. D. ___________________________ Wonpil Im, Ph. D. Date Defended: April 19, 2011 The Dissertation Committee for Grace Jepkorir Lagat certifies that this is the approved version of the following dissertation: STRUCTURAL AND BIOCHEMICAL INVESTIGATIONS OF THE MECHANISM OF HEME CAPTURE BY THE HEMOPHORE HasAp SECRETED BY PSEUDOMONAS AERUGINOSA Committee: ___________________________ Mario Rivera, Ph. D. (Chair) ___________________________ Robert C. Dunn, Ph. D. ___________________________ Susan Lunte, Ph. D. ___________________________ Mikhail Barybin, Ph. D. ___________________________ Minae Mure, Ph. D. ___________________________ Wonpil Im, Ph. D. Date Approved: April 19, 2011 ii ABSTRACT HasAp is a hemophore secreted by Pseudomonas aeruginosa to the extracellular media under iron limited conditions to sequester heme from the host cell. The heme HasAp complex is captured by the specific cell surface receptor HasR for subsequent internalization. X-ray and solution NMR structures of holo and apo hemophores have been solved but so far no studies have been done to elucidate the mechanism of heme loading. In the apo form, the loop bearing the distal heme iron ligand His 32 is located nearly 30 Å away from its position in the holo form.
    [Show full text]
  • Seed Storage Proteins As Sources of Bioactive Peptides
    In: Bioactive Molecules in Plant Foods ISBN: 978-1-62081-515-1 Editor: Florence Ojiugo Uruakpa © 2012 Nova Science Publishers, Inc. No part of this digital document may be reproduced, stored in a retrieval system or transmitted commercially in any form or by any means. The publisher has taken reasonable care in the preparation of this digital document, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained herein. This digital document is sold with the clear understanding that the publisher is not engaged in rendering legal, medical or any other professional services. Chapter II SEED STORAGE PROTEINS AS SOURCES OF BIOACTIVE PEPTIDES P. W. M. L. H. K. Marambe1 and J. P. D. Wanasundara2 1Department of Food and Bioproduct Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada 2Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, SK, Canada ABSTRACT Of all the food proteins, animal proteins, especially milk proteins, have been well researched in terms of the possibility of releasing bioactive peptides.However, plant proteins, particularly seed storage proteins (SSP) have received less attention compared to animal proteins in this respect. Several studies have identified SSP as sources of bioactive peptides with various bioactivities including antihypertensive, antioxidative, cholesterol lowering, immunomodulating and opioid activities. These peptides are inactive within the sequence of the precursor proteins and can be released due to proteolysis. Several studies have reported the ability of SSP to release bioactive peptides.
    [Show full text]