1bea: Difference between revisions
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==Overview== | ==Overview== | ||
Corn Hageman factor inhibitor (CHFI) is a bifunctional 127 residue, 13.6, kDa protein isolated from corn seeds. It inhibits mammalian trypsin and, Factor XIIa (Hageman Factor) of the contact pathway of coagulation as well, as alpha-amylases from several insect species. Among the plasma, proteinases, CHFI specifically inhibits Factor XIIa without affecting the, activity of other coagulation proteinases. We have isolated CHFI from corn, and determined the crystallographic structure at 1.95 A resolution., Additionally, we have solved the structure of the recombinant protein, produced in Escherichia coli at 2.2 A resolution. The two proteins are, essentially identical. The proteinase binding loop is in the canonical, conformation for proteinase inhibitors. In an effort to understand, ... | Corn Hageman factor inhibitor (CHFI) is a bifunctional 127 residue, 13.6, kDa protein isolated from corn seeds. It inhibits mammalian trypsin and, Factor XIIa (Hageman Factor) of the contact pathway of coagulation as well, as alpha-amylases from several insect species. Among the plasma, proteinases, CHFI specifically inhibits Factor XIIa without affecting the, activity of other coagulation proteinases. We have isolated CHFI from corn, and determined the crystallographic structure at 1.95 A resolution., Additionally, we have solved the structure of the recombinant protein, produced in Escherichia coli at 2.2 A resolution. The two proteins are, essentially identical. The proteinase binding loop is in the canonical, conformation for proteinase inhibitors. In an effort to understand, alpha-amylase inhibition by members of the family of 25 cereal, trypsin/alpha-amylase inhibitors, we have made three-dimensional models of, several proteins in the family based on the CHFI coordinates and the, coordinates determined for wheat alpha-amylase inhibitor 0.19 [Oda, Y., Matsunaga, T., Fukuyama, K., Miyazaki, T., and Morimoto, T. (1997), Biochemistry 36, 13503-13511]. From an analysis of the models and a, structure-based sequence analysis, we propose a testable hypothesis for, the regions of these proteins which bind alpha-amylase. In the course of, the investigations, we have found that the cereal trypsin/alpha-amylase, inhibitor family is evolutionarily related to the family of nonspecific, lipid-transfer proteins of plants. This is a new addition to the group, which now consists of the trypsin/alpha-amylase inhibitors, 2S seed, storage albumins, and the lipid-transfer family. Apparently, the, four-helix conformation has been a successful vehicle in plant evolution, for providing protection from predators, food for the embryo, and lipid, transfer. | ||
==About this Structure== | ==About this Structure== | ||
1BEA is a | 1BEA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Zea_mays Zea mays]. Structure known Active Site: SLE. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1BEA OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: serine protease inhibitor]] | [[Category: serine protease inhibitor]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:54:19 2007'' | ||
