1ppe

From Proteopedia

THE REFINED 2.0 ANGSTROMS X-RAY CRYSTAL STRUCTURE OF THE COMPLEX FORMED BETWEEN BOVINE BETA-TRYPSIN AND CMTI-I, A TRYPSIN INHIBITOR FROM SQUASH SEEDS (CUCURBITA MAXIMA): TOPOLOGICAL SIMILARITY OF THE SQUASH SEED INHIBITORS WITH THE CARBOXYPEPTIDASE A INHIBITOR FROM POTATOES

Overview

The stoichiometric complex formed between bovine beta-trypsin and the Cucurbita maxima trypsin inhibitor I (CMTI-I) was crystallized and its X-ray crystal structure determined using Patterson search techniques. Its structure has been crystallographically refined to a final R value of 0.152 (6.0-2.0 A). CMTI-I is of ellipsoidal shape; it lacks helices or beta-sheets, but consists of turns and connecting short polypeptide stretches. The disulfide pairing is CYS-3I-20I, Cys-10I-22I and Cys-16I-28I. According to the polypeptide fold and disulfide connectivity its structure resembles that of the carboxypeptidase A inhibitor from potatoes. Thirteen of the 29 inhibitor residues are in direct contact with trypsin; most of them are in the primary binding segment Val-2I (P4)-Glu-9I (P4') which contains the reactive site bond Arg-5I-Ile-6I and is in a conformation observed also for other serine proteinase inhibitors.

About this Structure

1PPE is a Protein complex structure of sequences from Bos taurus. Full crystallographic information is available from OCA.

Reference

The refined 2.0 A X-ray crystal structure of the complex formed between bovine beta-trypsin and CMTI-I, a trypsin inhibitor from squash seeds (Cucurbita maxima). Topological similarity of the squash seed inhibitors with the carboxypeptidase A inhibitor from potatoes., Bode W, Greyling HJ, Huber R, Otlewski J, Wilusz T, FEBS Lett. 1989 Jan 2;242(2):285-92. PMID:2914611

Page seeded by OCA on Sun Mar 30 23:02:49 2008