Crystallization, data collection and phasing of black-eyed pea trypsin/chymotrypsin inhibitor in complex with bovine
J A R G Barbosa1, R C L Teles, V P Forrer
1Centro de Biologia Molecular Estrutural (CeBiMe), Laboratório Nacional de Luz Síncrotron (LNLS), CP 6192, Campinas, SP, 13084-971, Brazil. joao@lnls.br
Abstract:
The black-eyed pea trypsin and chymotrypsin inhibitor (BTCI) is a Bowman-Birk-type inhibitor from Vigna unguiculata seeds. A complex of BTCI with bovine beta-trypsin was crystallized by the hanging-drop vapour-diffusion method with ammonium sulfate as precipitant. Crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 59.3, b = 61.8, c = 80.0 A. Diffraction data were collected to 2.36 A resolution and were processed to give an overall R(sym) of 0.137. The Matthews coefficient for one complex per asymmetric unit is 2.2 A(3) Da(-1), with a corresponding solvent content of 43%. After molecular replacement and initial refinement, the model gives an R(cryst) of 0.361 and an R(free) of 0.432.
