The active site of aspartic proteinases

The active site of the aspartic proteinase, endothiapepsin, has been defined by X‐ray analysis and restrained least‐squares refinement at 2.1 Å resolution with a crystallographic agreement value of 0.16. The environments of the two catalytically important aspartyl groups are remarkably similar and the contributions of the NH2‐ and COOH‐terminal domains to the catalytic centre are related by a local 2‐fold axis. The carboxylates of the aspartyls share a hydrogen bond and have equivalent contacts to a bound water molecule or hydroxonium ion lying on the local diad. The main chains around 32 and 215 are connected by a novel interaction involving diad‐related threonines. It is suggested that the two pK a, values of the active site aspartyls arise from a structure not unlike that in maleic acid with a hydrogen‐bonded intermediate species and a dicarboxylate characterised by electrostatic repulsions between the two negatively charged groups.

[1]  S. Bernhard,et al.  Spectrophotometric and structural evidence as to the mechanism of portease catalysis at chemical bonding resolution. , 1972, Cold Spring Harbor symposia on quantitative biology.

[2]  An X-ray crystallographic approach to enzyme structure and function. , 1980, Canadian journal of biochemistry.

[3]  M. James,et al.  Penicillopepsin from Penicillium janthinellum crystal structure at 2.8 Å and sequence homology with porcine pepsin , 1977, Nature.

[4]  L. Kuo,et al.  Catalytic conformation of carboxypeptidase A. The structure of a true reaction intermediate stabilized at subzero temperatures. , 1983, Journal of molecular biology.

[5]  J S Fruton,et al.  The mechanism of the catalytic action of pepsin and related acid proteinases. , 2006, Advances in enzymology and related areas of molecular biology.

[6]  T. Blundell,et al.  THE ACTIVE SITE OF ACID PROTEINASES , 1980 .

[7]  J. Kirkwood,et al.  The Electrostatic Influence of Substituents on the Dissociation Constants of Organic Acids. II , 1938 .

[8]  A. Fedorov,et al.  X-ray crystallographic studies of pepsin. , 1977, Advances in experimental medicine and biology.

[9]  M. James,et al.  Conformational flexibility in the active sites of aspartyl proteinases revealed by a pepstatin fragment binding to penicillopepsin. , 1982, Proceedings of the National Academy of Sciences of the United States of America.

[10]  K. Misono,et al.  Amino acid sequence of mouse submaxillary gland renin. , 1982, Proceedings of the National Academy of Sciences of the United States of America.

[11]  R. Kageyama,et al.  Cloning and sequence analysis of cDNA for human renin precursor. , 1983, Proceedings of the National Academy of Sciences of the United States of America.

[12]  M. James,et al.  Structure and refinement of penicillopepsin at 1.8 A resolution. , 1983, Journal of molecular biology.

[13]  T. Blundell,et al.  X-ray analysis and circular dichroism of the acid protease from Endothia parasitica and chymosin. , 1977, Advances in experimental medicine and biology.

[14]  F. Soubrier,et al.  Molecular cloning and nucleotide sequence of a human renin cDNA fragment. , 1983, Nucleic acids research.

[15]  D. Davies,et al.  Three-dimensional structure of the complex of the Rhizopus chinensis carboxyl proteinase and pepstatin at 2.5-A resolution. , 1982, Biochemistry.

[16]  M. James,et al.  Mechanism of acid protease catalysis based on the crystal structure of penicillopepsin , 1977, Nature.

[17]  Pierre Corvol,et al.  Complete amino acid sequence and maturation of the mouse submaxillary gland renin precursor , 1982, Nature.

[18]  T. Blundell,et al.  Homology among acid proteases: comparison of crystal structures at 3A resolution of acid proteases from Rhizopus chinensis and Endothia parasitica. , 1977, Proceedings of the National Academy of Sciences of the United States of America.

[19]  T. Blundell,et al.  The low resolution structure analysis of an acid proteinase from Endothia parasitica. , 1975, Journal of molecular biology.

[20]  J. Marciniszyn,et al.  Amino-acid sequence of porcine pepsin. , 1973, Proceedings of the National Academy of Sciences of the United States of America.