Acid Proteases: Structure, Function, and Biology -

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Résumé :
In the past ten years, a number of proceedings of symposia on the structure and function of proteolytic enzymes have been pub? lished. Their coverage of acid proteases has been limited, mainly due to the lack of significant new information on the structure of these enzymes. In the last four years, however, the primary and tertiary structures of a number of acid proteases have been deter? mined, prompting the need to discuss the meanings of the old data and the possibilities for new experimentations. It was for this purpose that the Conference on Acid Proteases: Structure, Function, and Biology was organized. It took place at the University of Oklahoma on November 21-24, 1976. This book is a collection of the main lectures delivered at the Conference. Acid Proteases, by definition refers to a group of proteases having an optimal pH in acidic solutions. The classic examples are pepsin and chymosin. Some catalytic features are obviously shared by these proteases, most notably, their inhibition by pepstatin. The use of active center-directed inactivators such as diazoacetyl? norleucine methyl ester and 1,2-epoxy-3-(p-nitrophenoxy)propane has shown that two catalytic aspartyl residues are present in most of these enzymes. These apparent cornmon features have prompted the suggestion by several investigators to name this group of enzymes aspartyl proteases or carboxyl proteases.

Sommaire:
Primary and Three-Dimensional Structure.- 1. Comparison of Primary Structures of Acid Proteases and their Zymogens.- 2. X-Ray Crystallographic Studies of Pepsin.- 3. The Crystal Structure of an Acid Protease from Rhizopus Chinensis at 2.5 A Resolution.- 4. X-Ray Analysis and Circular Dichroism of the Acid Protease from Endothia Parasitica and Chymosin.- 5. Penicillopepsin: 2.8 A Structure, Active Site Conformation and Mechanistic Implications.- Mechanism of Pepsinogen Activation.- 6. Intramolecular Activation of Pepsinogen.- 7. The First Cleavage Site in Pepsinogen Activation.- Catalytic Mechanism of Pepsin.- 8. Specificity and Mechanism of Pepsin Action on Synthetic Substrates.- 9. Subsite Specificity of Porcine Pepsin.- 10. Anhydride Intermediates in Catalysis by Pepsin: Is Pepsin an Enzyme with Two Active Sites?.- 11. New Data on Pepsin Mechanism and Specificity.- 12. Pepstatin Inhibition Mechanism.- 13. Chemical Modification of a Pepsin Inhibitor from the Activation Peptides of Pepsinogen.- Acid Proteases in Various Biological Systems.- 14. Renin and Precursors: Purification, Characterization, and Studies on Active Site.- 15. Inactive Renin - A Renin Proenzyme?.- 16. Characteristics and Functions of Proteinase A and Its Inhibitors in Yeast.- 17. Human Cathepsin D.- 18. Unique Biochemical and Biological Features of Cathepsin D in Rodent Lymphoid Tissues.- 19. Specificity and Biological Role of Cathepsin D.- 20. Acid Protease and its Proenzyme from Human Seminal Plasma.- List of Communications and Posters.- Conference Participants.