Jonathan Walton The Cyclic Peptide Toxins of Amanita and Other Poisonous Mushrooms The Cyclic Peptide Toxins of Amanita and Other Poisonous Mushrooms Amanita phalloides. (Drawing: Tamara Clark; tamaraclark.com) Jonathan Walton The Cyclic Peptide Toxins of Amanita and Other Poisonous Mushrooms Jonathan Walton United States Department of Energy Plant Research Lab and Department of Plant Biology Michigan State University East Lansing, MI, USA ISBN 978-3-319-76821-2 ISBN 978-3-319-76822-9 (eBook) https://doi.org/10.1007/978-3-319-76822-9 Library of Congress Control Number: 2018935145 © Springer International Publishing AG, part of Springer Nature 2018 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Printed on acid-free paper This Springer imprint is published by the registered company Springer International Publishing AG part of Springer Nature. The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland Preface Poisonous mushrooms have fascinated and horrified people for thousands of years. Mushrooms in the large and charismatic genus Amanita in particular have featured in countless historical anecdotes involving emperors, kings, and popes, and occur throughout popular culture from children’s stories to murder mysteries. Scientists have not been immune to the fascination of poisonous mushrooms, as attested by a professional literature of over 10,000 papers covering every aspect of the responsi- ble chemical principles. Three Nobel laureates have worked on the chemistry and biochemistry of the most deadly of the Amanita toxins – Heinrich Wieland (Nobel Prize 1927), his son-in-law Feodor Lynen (1964), and Roger Kornberg (2006). Lynen’s 1937 PhD dissertation on the isolation of phalloidin (“Über die Giftstoffe des Knollenblätterpilzes”) is available in many libraries. The peptide toxins of poi- sonous mushrooms continue to provide fertile ground for discoveries in toxicology, synthetic organic chemistry, enzymology, and fungal genomics. It is just one of the many remarkable traits of the Amanita cyclic peptides that the major toxins, amatoxins and phallotoxins, should have completely different cellular targets even though they are made by the same organisms through the same biosyn- thetic pathway and are chemically closely related. The amatoxins are potent and specific inhibitors of one of the most important enzymes in all eukaryotes, RNA polymerase II, whereas the phallotoxins bind with high affinity to actin, which com- prises the essential cytoskeleton of all eukaryotes and is central to the action of muscles. Recently, it has been found that poisonous Amanita mushrooms make doz- ens of additional and previously unknown cyclic peptides. Perhaps some of them will also have equally dramatic and diverse biological activities. This book owes a large debt to Theodore Wieland’s monograph on the same topic, Peptides of Poisonous Amanita Mushrooms (Springer 1986). Nonetheless, the current book is substantially different in content, primarily due to the immense progress that has been made on our understanding of all aspects of poisonous mush- rooms in the past 30 years. Most of our new knowledge has been made possible by extraordinary technical progress in the fields of chemistry and biology. The refine- ment and subsequent widespread adoption of HPLC, NMR spectroscopy, mass spectrometry (MS), and combinations thereof, especially LC/MS, have made toxin v vi Preface identification and quantitation easier, more sensitive, and more accurate. Advances in protein structure through X-ray crystallography have enabled a detailed under- standing of the interaction of α-amanitin with its target, RNA polymerase II, and of the enzymes involved in toxin biosynthesis. The exponential growth of the field of molecular genetics has impacted Amanita toxin research in numerous ways, includ- ing discovery of the toxin biosynthetic genes and new insights into the evolutionary relationships of poisonous mushrooms and other fungi. All this new knowledge has enabled new biotechnological and medical applications unforeseen by Professor Wieland. In addition to the desirability of updating its predecessor, a major impetus for writing this book was the author’s persistent struggle to become, and stay, educated about the multifarious/nefarious aspects of the Amanita toxins. Among both lay- people and scientists, the same questions tend to arise over and over: Why do the mushrooms make them? How are the toxins taken up by cells and organs? Which chemical functional groups are critical for activity? Why are they so toxic? Do edi- ble mushrooms make the toxins? How are they biosynthesized? How did toxin bio- synthesis evolve multiple times in unrelated mushroom lineages? Answering these questions to my own satisfaction required an immersion in a large and often contra- dictory literature, much of it dating back half a century or more. Every time I had educated myself on one of these questions, it seemed logical to write down the rel- evant citations and, when possible, the answers, before they were forgotten. Thus, the essence of this book took shape. In this day and age, no one can expect to be expert in all the fields touched upon by the Amanita cyclic peptides, and the author can claim to be an expert in only one or two relevant subdisciplines. It is impossible to cover so much scientific territory – chemistry, mycology, biochemistry, ecology, evolution, etc. – without making numerous errors and risking offense to honored colleagues with misrepresentations (or, worse, neglect) of their inestimable contributions. In this interactive age, it seems reasonable to extend an invitation to readers to communicate their comments and corrections (email: [email protected]), toward the eventual establishment of a discussion forum that could benefit the entire Amanita toxin community. In the meantime, please accept the author’s apologies for the inevitable inaccuracies and oversights. East Lansing, MI, USA Jonathan Walton Acknowledgments Since I knew little about poisonous mushrooms until relatively late in my career as a plant physiologist/fungal molecular biologist, I owe a huge debt to the many peo- ple who generously shared their knowledge and passion. In particular, I am grateful to the members of my laboratory who took our understanding of the Amanita cyclic peptides into uncharted territory, especially Heather Hallen-Adams (currently in the Food Science and Technology Department, University of Nebraska-Lincoln), Hong Luo (Kunming Institute of Botany, Chinese Academy of Sciences), John Scott-­ Craig, Richard Ransom (Funite, LLC, and University of Michigan), and R. Michael Sgambelluri. I would like to thank Rod Tulloss, who runs the world’s best website on all things Amanita (www.amanitaceae.org), and Britt Bunyard, the publisher and Editor-in-­ Chief of Fungi magazine (www.fungimag.com). Both not only supplied specimens but also condescended to edify this neophyte about the nuances of Amanita taxon- omy; together we someday hope to resolve “cryptic speciation” in A. bisporigera, in my mind a question of major importance for understanding the evolutionary origins and depth of cyclic peptide diversity. I thank Todd Mitchell, MD, for his pioneering efforts to bring the amanitin antidote, silybin (Legalon® SIL), to the United States, and for informative discussions on the medical aspects of peptide toxin poisonings at Gayle’s Bakery in Capitola. My Chinese colleagues Zhuliang Yang (Kunming Institute of Botany, Chinese Academy of Sciences), Zuohong Chen (Hunan Normal University), and Tai-hui Li (Guangdong Institute of Microbiology, Guangzhou) have not only made many outstanding contributions to Amanita biology and toxi- cology but also generously shared their knowledge and hospitality. Debbie Viess and David Rust (Bay Area Mycological Society), organizers of the annual Pt. Reyes Fungus Fair, shared their leftover specimens with me. Catherine (Cat) Adams (University of California, Berkeley) took me on an excursion to collect A. phalloides in Marin County. Else Vellinga and Tom Bruns (UC Berkeley), Mary Berbee and Brandon Landry (University of British Columbia), Britney Ramsey (Oregon), Joshua Birkebak (Assured Bio, Oakridge, TN), Sara Epis and Davide Sassera (Universitá degli Studi di Milano), Randy Garrett (Pacific Collegiate School, Santa Cruz), Anne Pringle (University of Wisconsin, Madison), and Adolf