1G9I

CRYSTAL STRUCTURE OF BETA-TRYSIN COMPLEX IN CYCLOHEXANE

Summary for 1G9I

• Entry DOI: 10.2210/pdb1g9i/pdb
• Related: 1SMF
• Descriptor: TRYPSINOGEN, CATIONIC, BOWMAN-BIRK TYPE TRYPSIN INHIBITOR, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: trypsin-inhibitor complex, organic media, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• Biological source: Bos taurus (cattle); More
• Cellular location: Secreted, extracellular space: P00760
• Total number of polymer chains: 2
• Total formula weight: 25968.31

Authors

Zhu, G.,Huang, Q.,Zhu, Y.,Li, Y.,Chi, C.,Tang, Y. (deposition date: 2000-11-24, release date: 2000-12-06, Last modification date: 2024-11-13)

Primary citation

Zhu, G.,Huang, Q.,Zhu, Y.,Li, Y.,Chi, C.,Tang, Y.
X-Ray study on an artificial mung bean inhibitor complex with bovine beta-trypsin in neat cyclohexane.
Biochim.Biophys.Acta, 1546:98-106, 2001

PubMed Abstract: The active trypsin inhibiting component, SPC1, was obtained during the synthesis of a 22-residue peptide with three disulfide bridges according to the mimic mung bean Bowman-Birk type inhibitor. The K(i) value of SPC1 is 1.2x10(-7) M. In order to determine the topological structure of SPC1, X-ray diffraction studies were carried out on the complex of SPC1 with bovine beta-trypsin. Only the binding loop of SPC1 resolved at 2.2 A resolution due to conformational flexibility of the other residues [1]. The amino acid sequence was re-determined and electrospray mass spectroscopy was also performed to ensure that no cleaving occurred on SPC1 and the primary sequence of SPC1 is correct. Because the protein is more rigid in nonaqueous medium as has been proved by others [2], we treated the complex of SPC1 with neat cyclohexane and then subjected it to X-ray diffraction analysis, and the result showed that all the 22 residues of SPC1 were located in the electron density map. So the topological structure of SPC1 has been determined, suggesting that crystal treatment with cyclohexane may be used as a method to determine the conformation of the disordered regions in protein crystal structures.

PubMed: 11257512
DOI: 10.1016/S0167-4838(00)00299-5

Experimental method

X-RAY DIFFRACTION (2.2 Å)