title: Crystallization and preliminary X-ray crystallographic study of the leech protease inhibitor guamerin and its complex with bovine pancreatic chymotrypsin.
abstract: Guamerin, a small peptide inhibitor of the serine protease from Hirudo nipponia, was expressed in yeast and crystallized using the vapor diffusion method, with MPD as precipitant. The crystal was found to belong to the monoclinic P2(1) space group with unit cell parameters a=136.06, b=206.59, c=227.39 A, beta=105.03 degrees. The guamerin/bovine pancreatic chymotrypsin complex was also crystallized using PEG 8K as precipitant. The space group was identified as P2(1)2(1)2(1) with unit cell parameters of a=44.01, b=44.30, c=122.47 A. The diffraction data of the complex were collected up to a resolution of 2.4 A using a synchrotron-radiation source under cryogenic condition.
authors.affiliation: Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea.
authors.forename: Dong Ryoung
authors.initials: DR
authors.lastname: Kim
authors.forename: Dong Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Trang Thi Thu
authors.initials: TT
authors.lastname: Chu
authors.forename: Kyung-Hwan
authors.initials: KH
authors.lastname: Jung
authors.forename: Kyeong Kyu
authors.initials: KK
authors.lastname: Kim
mesh_terms: D000818:Animals; D002417:Cattle; D002918:Chymotrypsin / Q000737:chemistry* / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D007447:Invertebrate Hormones / Q000737:chemistry / Q000378:metabolism*; D007865:Leeches / Q000378:metabolism*; D010179:Pancreas / Q000201:enzymology*; D011480:Protease Inhibitors / Q000737:chemistry*
chemical_list: D007447:Invertebrate Hormones; D011480:Protease Inhibitors; C093975:guamerin; D002918:Chymotrypsin