Crystallization and preliminary X-ray analysis of a novel Kunitz-type kallikrein inhibitor from Bauhinia bauhinioides

Journal Article · Sat Oct 01 04:00:00 EDT 2005 · Acta Crystallographica. Section F

DOI:https://doi.org/10.1107/S1744309105028496· OSTI ID:22356228

Vierira, Débora F. ^[1]; Nagem, Ronaldo A. P. ^[2]; Oliva, Maria Luiza V. ^[3]

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1. Institute of Physics of São Carlos, University of São Paulo, Avenida Trabalhador Sãocarlense 400, CEP 13560-970, São Carlos, SP (Brazil)
2. Biochemistry and Immunology Department, Institute of Biological Sciences, Federal University of Minas Gerais, Avenida Antônio Carlos 6627, Caixa Postal 486, CEP 31270-901, Belo Horizonte, MG (Brazil)
3. Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Três de Maio 100, CEP 04044-020, São Paulo, SP (Brazil)

Crystallization and preliminary X-ray diffraction studies are reported for a novel Kunitz-type protease inhibitor from B. bauhinioides which contains no disulfide bridges. A Kunitz-type protease inhibitor (BbKI) found in Bauhinia bauhinioides seeds has been overexpressed in Escherichia coli and crystallized at 293 K using PEG 4000 as the precipitant. X-ray diffraction data have been collected to 1.87 Å resolution using an in-house X-ray generator. The crystals of the recombinant protein (rBbKI) belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 46.70, b = 64.14, c = 59.24 Å. Calculation of the Matthews coefficient suggests the presence of one monomer of rBbKI in the asymmetric unit, with a corresponding solvent content of 51% (V{sub M} = 2.5 Å{sup 3} Da{sup −1}). Iodinated crystals were prepared and a derivative data set was also collected at 2.1 Å resolution. Crystals soaked for a few seconds in a cryogenic solution containing 0.5 M NaI were found to be reasonably isomorphous to the native crystals. Furthermore, the presence of iodide anions could be confirmed in the NaI-derivatized crystal. Data sets from native and derivative crystals are being evaluated for use in crystal structure determination by means of the SIRAS (single isomorphous replacement with anomalous scattering) method.

• OSTI ID: 22356228
• Journal Information: Acta Crystallographica. Section F, Journal Name: Acta Crystallographica. Section F Journal Issue: Pt 10 Vol. 61; ISSN ACSFCL; ISSN 1744-3091
• Country of Publication: United Kingdom
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANIONS
CRYSTAL STRUCTURE
CRYSTALLIZATION
CRYSTALS
ESCHERICHIA COLI
MATHEMATICAL SOLUTIONS
MONOMERS
RESOLUTION
SOLUTIONS
SOLVENTS
SPACE GROUPS
X-RAY DIFFRACTION