Download MendeleyCrystal structure of the bifunctional soybean Bowman-Birk inhibitor at 0.28-nm resolution. Structural peculiarities in a folded protein conformation.
Voss, R.H., Ermler, U., Essen, L.O., Wenzl, G., Kim, Y.M., Flecker, P.(1996) Eur J Biochem 242: 122-131
- PubMed: 8954162
- DOI: https://doi.org/10.1111/j.1432-1033.1996.0122r.x
- Primary Citation of Related Structures:
1K9B - PubMed Abstract:
The Bowman-Birk inhibitor from soybean is a small protein that contains a binary arrangement of trypsin-reactive and chymotrypsin-reactive subdomains. In this report, the crystal structure of this anticarcinogenic protein has been determined to 0.28-nm resolution by molecular replacement from crystals grown at neutral pH. The crystal structure differs from a previously determined NMR structure [Werner, M. H. & Wemmer, D. E. (1992) Biochemistry 31, 999-1010] in the relative orientation of the two enzyme-insertion loops, in some details of the main chain trace, in the presence of favourable contacts in the trypsin-insertion loop, and in the orientation of several amino acid side chains. The proximity of Met27 and Gln48 in the X-ray structure contradicts the solution structure, in which these two side chains point away from each other. The significant effect of a Met27-->Ile replacement on the inhibitory activity of the chymotrypsin-reactive subdomain agrees with the X-ray structure. Exposed hydrophobic patches, the presence of charged amino acid residues, and the presence of water molecules in the protein interior are in contrast to standard proteins that comprise a hydrophobic core and exposed polar amino acids.
Organizational Affiliation:
Max-Planck-Institut für Biophysik, Frankfurt am Main, Germany.
