1E37

PORCINE PANCREATIC ELASTASE COMPLEXED WITH (3S, 4S)N-PARA-NITROBENZENESULPHONYL -3-ETHYL-4-(CARBOXYLIC ACID)PYRROLIDIN-2-ONE SOAKED IN PH 9 BUFFER FOR 1 MINUTE

Summary for 1E37

• Entry DOI: 10.2210/pdb1e37/pdb
• Related: 1B0E 1BMA 1BTU 1E34 1E35 1E36 1E38 1EAI 1EAS 1EAT 1EAU 1ELA 1ELB 1ELC 1ELD 1ELE 1ELF 1ELG 1ESA 1ESB 1EST 1INC 1JIM 1LVY 1NES 1QGF 2EST 3EST 4EST 5EST 6EST 7EST 8EST 9EST
• Descriptor: ELASTASE, CALCIUM ION, SULFATE ION, ... (5 entities in total)
• Functional Keywords: hydrolase(serine protease), serine protease, hydrolase, serine proteinase
• Biological source: SUS SCROFA (WILD BOAR)
• Cellular location: Secreted: P00772
• Total number of polymer chains: 1
• Total formula weight: 26408.51

Authors

Wright, P.A.,Wilmouth, R.C.,Clifton, I.J.,Schofield, C.J. (deposition date: 2000-06-06, release date: 2000-10-18, Last modification date: 2023-12-06)

Primary citation

Wright, P.A.,Wilmouth, R.C.,Clifton, I.J.,Schofield, C.J.
'Ph-Jump' Crystallographic Analyses of Gamma-Lactam-Porcine Pancreatic Elastase Complexes
Biochem.J., 351:335-, 2000

PubMed Abstract: beta-Lactams inhibit a range of enzymes via acylation of nucleophilic serine residues. Certain gamma-lactam analogues of monocyclic beta-lactams have also been shown to be reversible inhibitors of porcine pancreatic elastase (PPE), forming acyl-enzyme complexes that are stable with respect to hydrolysis. Crystallographic analysis at pH 5 of an acyl-enzyme complex formed with PPE and one of these inhibitors revealed the ester carbonyl located in the oxyanion hole in a similar conformation to that observed in the structure of a complex formed between a heptapeptide (beta-casomorphin-7) and PPE. Only weak electron density was observed for the His-57 side chain in its 'native' conformation. Instead, the His-57 side chain predominantly adopted a conformation rotated approx. 90 degrees from its normal position. PPE-gamma-lactam crystals were subjected to 'pH-jumps' by placing the crystals in a buffer of increased pH prior to freezing for data collection. The results indicate that the conformation of the gamma-lactam-derived acyl-enzyme species in the PPE active site is dependent on pH, a result having implications for the analysis of other serine protease-inhibitor structures at non-catalytic pH values. The results help to define the stereoelectronic relationship between the ester of the acyl-enzyme complex, the side chain of His-57 and the incoming nucleophile during the reversible (de)acylation steps, implying it is closely analogous to the hydrolytic deacylation step during catalytic peptide hydrolysis.

PubMed: 11023818
DOI: 10.1042/0264-6021:3510335

Experimental method

X-RAY DIFFRACTION (1.75 Å)