1bea
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Corn Hageman factor inhibitor (CHFI) is a bifunctional 127 residue, 13.6 | + | 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== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Zea mays]] | [[Category: Zea mays]] | ||
| - | [[Category: Behnke, C | + | [[Category: Behnke, C A.]] |
| - | [[Category: Kim, S | + | [[Category: Kim, S S.]] |
| - | [[Category: Pedersen, L | + | [[Category: Pedersen, L C.]] |
| - | [[Category: Reeck, G | + | [[Category: Reeck, G R.]] |
| - | [[Category: Stenkamp, R | + | [[Category: Stenkamp, R E.]] |
| - | [[Category: Teller, D | + | [[Category: Teller, D C.]] |
| - | [[Category: Trong, I | + | [[Category: Trong, I Le.]] |
| - | [[Category: Yee, V | + | [[Category: Yee, V C.]] |
[[Category: amylase/protease bifunctional inhibitor]] | [[Category: amylase/protease bifunctional inhibitor]] | ||
[[Category: serine protease inhibitor]] | [[Category: serine protease inhibitor]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:54:21 2008'' |
Revision as of 09:54, 21 February 2008
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BIFUNCTIONAL HAGEMAN FACTOR/AMYLASE INHIBITOR FROM MAIZE
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 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
1BEA is a Single protein structure of sequence from Zea mays. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Structural determinants of the bifunctional corn Hageman factor inhibitor: x-ray crystal structure at 1.95 A resolution., Behnke CA, Yee VC, Trong IL, Pedersen LC, Stenkamp RE, Kim SS, Reeck GR, Teller DC, Biochemistry. 1998 Nov 3;37(44):15277-88. PMID:9799488
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