Crystal structures of a plant trypsin inhibitor from Enterolobium contortisiliquum (EcTI) and of its complex with bovine trypsin.

ABSTRACT: A serine protease inhibitor from Enterolobium contortisiliquum (EcTI) belongs to the Kunitz family of plant inhibitors, common in plant seeds. It was shown that EcTI inhibits the invasion of gastric cancer cells through alterations in integrin-dependent cell signaling pathway. We determined high-resolution crystal structures of free EcTI (at 1.75 Å) and complexed with bovine trypsin (at 2 Å). High quality of the resulting electron density maps and the redundancy of structural information indicated that the sequence of the crystallized isoform contained 176 residues and differed from the one published previously. The structure of the complex confirmed the standard inhibitory mechanism in which the reactive loop of the inhibitor is docked into trypsin active site with the side chains of Arg6

SUBMITTER: Zhou D 

PROVIDER: S-EPMC3633903 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature