1kio
From Proteopedia
SOLUTION STRUCTURE OF THE SMALL SERINE PROTEASE INHIBITOR SGCI[L30R, K31M]
Overview
The solution structure of three small serine proteinase inhibitors, two natural and one engineered protein, SGCI (Schistocerca gregaria chymotrypsin inhibitor), SGCI[L30R, K31M] and SGTI (Schistocerca gregaria trypsin inhibitor), were determined by homonuclear NMR-spectroscopy. The molecules exhibit different specificities towards target proteinases, where SGCI is a good chymotrypsin inhibitor, its mutant is a potent trypsin inhibitor, and SGTI inhibits both proteinases weakly. Interestingly, SGTI is a much better inhibitor of insect proteinases than of the mammalian ones used in common assays. All three molecules have a similar fold composed from three antiparallel beta-pleated sheets with three disulfide bridges. The proteinase binding loop has a somewhat distinct geometry in all three peptides. Moreover, the stabilization of the structure is different in SGCI and SGTI. Proton-deuterium exchange experiments are indicative of a highly rigid core in SGTI but not in SGCI. We suggest that the observed structural properties play a significant role in the specificity of these inhibitors.
About this Structure
1KIO is a Single protein structure. Full crystallographic information is available from OCA.
Reference
Comparative structure analysis of proteinase inhibitors from the desert locust, Schistocerca gregaria., Gaspari Z, Patthy A, Graf L, Perczel A, Eur J Biochem. 2002 Jan;269(2):527-37. PMID:11856311 Page seeded by OCA on Fri May 2 22:47:38 2008
