Determination of the X-ray structure of the snake venom protein omwaprin by total chemical synthesis and racemic protein crystallography

作者：Banigan James R; Mandal Kalyaneswar; Sawaya Michael R; Thammavongsa Vi****k; Hendrickx Antoni P A; Schneewind Olaf; Yeates Todd O; Kent Stephen B H^*

来源：Protein Science, 2010, 19(10): 1840-1849.

DOI：10.1002/pro.468

• omwaprin
• chemical protein synthesis
• racemic crystallography
• direct methods
• venom protein

The 50-residue snake venom protein L-omwaprin and its enantiomer D-omwaprin were prepared by total chemical synthesis. Radial diffusion assays were performed against Bacillus megaterium and Bacillus anthracis; both L- and D-omwaprin showed antibacterial activity against B. megaterium. The native protein enantiomer, made of L-amino acids, failed to crystallize readily. However, when a racemic mixture containing equal amounts of L- and D-omwaprin was used, diffraction quality crystals were obtained. The racemic protein sample crystallized in the centrosymmetric space group P2(1)/c and its structure was determined at atomic resolution (1.33 angstrom) by a combination of Patterson and direct methods based on the strong scattering from the sulfur atoms in the eight cysteine residues per protein. Racemic crystallography once again proved to be a valuable method for obtaining crystals of recalcitrant proteins and for determining high-resolution X-ray structures by direct methods.

• 出版日期2010-10