NewApproaches far Antifungal Drugs New Approaches Jor Antifungal Drugs Prabhavathi B. Fernandes Editor Springer Science+Business Media, LLC Prabhavathi B. Femandes Department of Microbial Molecular Biology Bristol Myers Squibb Pharmaceutical Research Institute Princeton, New Jersey 08543 Library of Congress in Publication Data New approaches for antifungal drugs I edited by Prabhavathi B. Femandes. p. cm. Includes bibliographical references and index. ISBN 978-1-4899-6731-2 ISBN 978-1-4899-6729-9 (eBook) DOI 10.1007/978-1-4899-6729-9 l. Antifungal agents. I. Fernandes, P. B. (Prabhavathi B. ) [DNLM: l. Antifungal Agents. QV 252 N532] RM41O. N48 1992 616.969061--dc20 DNLM/DLC 92-11106 for Library of Congress CIP Printed on acid-free paper. © Springer Science+Business Media New York 1992 Originally published by Birkhäuser Boston in 1992. Softcover reprint of hardcover 1s t edition 1992 Copyright is not claimed for works of V.S. Government employees. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system,or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior permission of the copyright owner. The use of general descriptive names, trademarks, etc. in this publication, even ifthe former are not especially identified, is not to be taken as a sign that such names, as understood by the Trade Marks and Merchandise Marks Act, may accordingly be used freely by anyone. While the advice and information in this book are believed to be true and accurate at the date of going to press, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied with respect to the material contained herein. Permission to photocopy for internal or personal use of specificclients is granted by Birkhäuser Boston for libraries and other users registered with the Copyright Clearance Center (CCC), provided that the base fee of $0.00 per copy, plus $0.20 per page is paid directIy to CCC, 21 Congress Street, Salem, MA 01970, V.S.A. Special reguests should be addressed directIy to Birkhäuser Boston, 675 Massachusetts Avenue, Cambridge, MA 02139, V.S.A. Typset by ARK Publications, Inc., Newton Centre, MA 987654321 TABLE OF CONTENTS Preface Prabhavathi B. Fernandes vii List of Contributors IX The Need for New Antifungal Drugs Alice M. Clark ........ . . . . . . . . I (1 -- 6) - ß-Glucan Biosynthesis: Potential Targets for Antifungal Drugs Howard Bussey, Charles Boone, leffrey Brown, Kathryn Hill, Terry Roemer, and Anne-Marie Sdicu .. 20 Importance of Chitin Synthesis for Fungal Growth and as a Target for Antifungal Agents lohn E. McCullough . . . . . . . . . . . . . . . . . . 32 The Fungal Cell Wall - A Target For Lipopeptide Antifungal Agents Robert S. Gordee, Manuel Debono, and Thomas R. Parr, Ir. . . . 46 Pradimicin, A Novel Antifungal Agent Toshikazu Oki . . . . . . . . . . . . ... 64 Antifungal Proteins from Plants: A Possible New Source of Human Therapeutics Claude P. Selitrennikoff, Alison I. Vigers, and Waiden K. Roberts. 88 Elongation Factor 3 - A Unique Fungal Protein Kalpana Chakraburtty . . . . . . . . . . . 114 Genetic Approaches to Antifungal Drug Discovery Jessica A. Gorman .......... ....... 143 Sterol 14o:-Demethylase: Target of the Azole Antifungal Agents S. L. Kelly, M. A. Quail, J. Rowe, and D. E. Kelly . . . . . . . 155 Amphotericin B Phospholipid Formulations Junius M. Clark . . . . . . . . . . . . . . . . . . . . . 188 Index . . . . . . . . . . . . . . . . . . . . . . . . . 197 PREFACE The chemotherapy of fungal diseases has progressed far less than that of bacterial diseases. In spite of intensive efforts by many pharmaceutical companies, progress beyond the major anti-fungal agents, amphotericin Band the azoles has not yet been achieved. The main reason for the lack of new drugs against fungal infections is the eukaryotic nature of fungi, making selective therapy a more difficult task. The need for new antifungal agents has become more prominent because of the increase in the number of fungal infections which occurs in patients who are immunocompromised and those with indwelling devices. In the last decade a large effort has been made to find novel targets for antifungal therapy. In this book, many of these selective targets are described. In the first chapter, Dr. Alice Clark has addressed the need for new antifungal agents and a philosophical discussion of the approaches to screening to find novel pharmacophores. The fungal cell wall, made of chitin, glucan and mannan, provides several selective targets just as peptidoglycan has provided targets for chemotherapy against bacteria. Three chapters, one by Dr. Bussey and co-workers on (l-6)-ß-glucan biosynthesis, the second by Dr. McCullough on chitin synthases and a third chapter by Dr. Gordee and co-workers on novel antifungal agents which are directed against (l-3)-ß-glucan describes the efforts in the cell wall area. The search for antifungal agents has lead to the identification of novel pharmacophores, exemplified by pradimicin. In the chapter on pradimicin, Dr. Oki describes the novel mechanism by which it kills fungi, i.e., by binding mannan on the cell wall which somehow results in cell membrane damage. While examining plant natural products for anti-fungal activity, Dr. Selitrennikoff and colleagues have characterized a novel c1ass of anti-fungal agents, the permatins, which have activity against the fungal cell membrane. Since fungi are eukaryotic cells, the cellular machinery involved in protein synthesis had not been considered as a selective target until recently, with the discovery that elongation factor 3 (EF-3) is found exc1u sively in fungal cells and is essential to the fungal cello Dr. Chakraburtty viii Preface describes the advances made in the EF-3 area and the potential for using this target to find novel anti-fungal agents. The application of molecular biology and recombinant DNA techno logy to pathogenic fungi is leading to a better understanding of the biology of these organisms. In addition, these methods have allowed the cloning of essential genes and identification of targets for anti-fungal therapy. Dr. Gorman describes the molecular approaches which have been taken to analyze Candida albicans in order to be able to use genetic techniques in this diploid organism which has no known sex ual cycle. Lanosterol demethylase, an enzyme in the sterol biosynthesis path way, is the target for the azole class of antifungal agents which have been extensively studied. Several drugs from this class are used clinically. A chapter by Dr. Kelly and co-workers has been included on the biology of this enzyme as it has the potential of being inhibited by pharmacophores other than azoles. Although progress has been made in identifying new antifungal agents, amphotericin B has remained the most effective antifungal agent. The use of this drug has been extended by reducing its toxicity by formu lating it with lipids. Dr. Clark describes the efficacy and reduced toxicity of these lipid formulations. In conclusion, this book is directed toward the understanding of potentially useful target agents and the methods taken to identify new targets. I thank the authors, each recognized for their important contri butions, for their cooperation in submitting their chapters to me in a timely manner. Prabhavathi B. Femandes Executive Director, Microbial Molecular Biology and Natural Products Research Bristol Myers Squibb Pharmaceutical Research Institute List of Contributors Charles Boone, Department of Biology, McGiIl University, 1205 Avenue Dr. Penfield, Montreal, Quebec Canada H3A IBI Jeffrey Brown, Department of Biology, McGill University, 1205 Avenue Dr. Penfield, Montreal, Quebec Canada H3A IBI Howard Bussey, Department of Biology, McGiIl University, 1205 Avenue Dr. Penfield, Montreal, Quebec Canada H3A 1B 1 Kalpana Chakraburtty, Ph. D., Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226 Alice M. Clark, Research Institute of Pharmaceutical Sciences, School of Phar macy, The University of Mississippi, University, MS 38677 Junius M. Clark, Bristol-Myers Squibb Pharmaceutical Research Institute, 5 Research Parkway, Wallingford, CT 06492-7660 Manuel Debono, The Lilly Research Laboratories, Eli Lilly & Company, Lilly Corporate Center, Indianapolis, IN 46285-1533 Dr. Prabhavathi B. Fernandes, Executive Director, Department of Microbial Molecular Biology, Bristol-Myers Squibb Pharmaceutical Research Institute, P. O. Box 4000, Princeton, NJ 08543-4000 Robert S. Gordee, The Lilly Research Laboratories, Eli Lilly & Company, Lilly Corporate Center, Indianapolis, IN 46285-0428 Jessica A. Gorman, Department of Microbial Molecular Biology, Bristol-Myers Squibb Pharmaceutical Research Institute, P. O. Box 4000, Princeton, NJ 08543-4000 Kathryn Hili, Department of Biology, McGill University, 1205 Avenue Dr. Penfield, Montreal, Quebec Canada H3A 1B 1 Steven L. Kelly, The University of Sheffield, Kreb Institute, Western Bank, Sheffield S 10 2TN England D. E. Kelly, The University of Sheffield, Kreb Institute, Western Bank, Sheffield S 10 2TN England John E. McCuliough, Department of Microbial Molecular Biology, The Bristol Myers Squibb Institute for Medical Research, P. O. Box 4000, Princeton, NJ 08543-4000 x List of Contributors Toshikazu Oki, Bristol-Myers Squibb Research Institute, 2-9-3, Shimo-meguro, Meguro-Ku, Tokyo 153 Japan Thomas R. Parr, Jr., The Lilly Research Laboratories, Eli Lilly & Company, Lilly Corporate Center, Indianapolis, IN 46285-0428 M. A. Quai!, , The University of Sheffield, Kreb Institute, Western Bank, Sheffield S 10 2TN England Waiden K. Roberts, Department of Microbiology & Immunology, University of Colorado Health Sciences Center, Denver, CO 80262 Terry Roemer, Department of Biology, McGilI University, 1205 Avenue Dr. Pen field, Montreal, Quebec Canada H3A IBI J. Rowe. . The University of Sheffield, Kreb Institute, Western Bank, Sheffield S 10 2TN England Anne-Marie Sdicu, Department of Biology, McGilI University, 1205 Avenue Dr. Penfield, Montreal, Quebec Canada H3A 1B I Claude P. Selitrennikoff, Mycotox, Inc., B-lll, 4200 E. Ninth Avenue, Denver, CO 80262 Alison J. Vigers, Department of Cellular & Structural Biology, University of Colorado Health Sciences Center, Denver, CO 80262