Open AccessCrystallization and preliminary crystallographic studies of Schizolobium parahyba chymotrypsin inhibitor (SPCI) at 1.8 Å resolution
Author(s) -
Teles Rozeni Chagas Lima,
Esteves Gisele Ferreira,
Araújo Marcus Aurélio Miranda,
Bloch Carlos,
Barbosa João Alexandre Ribeiro Gonçalves,
De Freitas Sonia Maria
Publication year - 2007
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309107045393
Subject(s) - crystallization , ammonium sulfate , chemistry , chymotrypsin , sodium , resolution (logic) , protein data bank (rcsb pdb) , trypsin inhibitor , crystallography , trypsin , nuclear chemistry , chromatography , stereochemistry , biochemistry , enzyme , organic chemistry , artificial intelligence , computer science
SPCI, a Kunitz‐type chymotrypsin inhibitor, is a 180‐amino‐acid polypeptide isolated from Schizolobium parahyba seeds. This inhibitor has been characterized as a highly stable protein over a broad pH and temperature range. SPCI was crystallized using a solution containing 0.1 M sodium acetate trihydrate buffer pH 4.6, 33%( v / v ) PEG 2000 and 0.2 M ammonium sulfate. Data were collected to 1.80 Å resolution from a single crystal of SPCI under cryogenic conditions. The protein crystallized in space group P 2 1 2 1 2, with unit‐cell parameters a = 40.01, b = 71.58, c = 108.68 Å and an R merge of 0.052. The structure of SPCI has been solved by molecular replacement using the known structure of the Kunitz‐type trypsin inhibitor from Delonix regia (PDB code 1r8n ) as the search model.