PDBsum entry 2v35

Hydrolase

PDB id: 2v35

Contents

Protein chain

240 a.a. *

Ligands

J54

SO4

GOL ×2

Metals

_NA

Waters ×310

* Residue conservation analysis

PDB id:

2v35

Name:

Hydrolase

Title:

Porcine pancreatic elastase in complex with inhibitor jm54

Structure:

Elastase-1. Chain: a. Synonym: porcine pancreatic elastase. Ec: 3.4.21.36

Source:

Sus scrofa. Pig. Organism_taxid: 9823. Organ: pancreas

Resolution:

1.67Å R-factor: 0.158 R-free: 0.186

Authors:

T.F.Oliveira,J.Mulchande,L.Martins,R.Moreira,J.Iley,M.Archer

Key ref:

J.Mulchande et al. (2007). The efficiency of C-4 substituents in activating the beta-lactam scaffold towards serine proteases and hydroxide ion. Org Biomol Chem, 5, 2617-2626. PubMed id: 18019537

Date:

12-Jun-07 Release date: 24-Jun-08

Protein chain

P00772  (CELA1_PIG) -  Chymotrypsin-like elastase family member 1 from Sus scrofa

Seq: 266 a.a.

Struc: 240 a.a.

Enzyme reactions

• Enzyme class: E.C.3.4.21.36 - pancreatic elastase.
• Reaction: Hydrolysis of proteins, including elastin. Preferential cleavage: Ala-|-Xaa.

Org Biomol Chem 5:2617-2626 (2007)

PubMed id: 18019537

The efficiency of C-4 substituents in activating the beta-lactam scaffold towards serine proteases and hydroxide ion.

J.Mulchande, L.Martins, R.Moreira, M.Archer, T.F.Oliveira, J.Iley.

ABSTRACT

The presence of a leaving group at C-4 of monobactams is usually considered to be a requirement for mechanism-based inhibition of human leukocyte elastase by these acylating agents. We report that second-order rate constants for the alkaline hydrolysis and elastase inactivation by N-carbamoyl monobactams are independent of the pKa of the leaving group at C-4. Indeed, the effect exerted by these substituents is purely inductive: electron-withdrawing substituents at C-4 of N-carbamoyl-3,3-diethylmonobactams increase the rate of alkaline hydrolysis and elastase inactivation, with Hammett pI values of 3.4 and 2.5, respectively, which indicate the development of a negative charge in the transition-states. The difference in magnitude between these pI values is consistent with an earlier transition-state for the enzymatic reaction when compared with that for the chemical process. These results suggest that the rate-limiting step in elastase inactivation is the formation of the tetrahedral intermediate, and that beta-lactam ring-opening is not concerted with the departure of a leaving group from C-4. Monobactam sulfones emerged as potent elastase inhibitors even when the ethyl groups at C-3, required for interaction with the primary recognition site, are absent. For one such compound, a 1 : 1 enzyme-inhibitor complex involving porcine pancreatic elastase has been examined by X-ray crystallography and shown to result from serine acylation and sulfinate departure from the beta-lactam C-4.