Crystallographic refinement of trichosanthin at 2.6A resolution.

ABSTRACT

The molecule model of trichosanthin has been rebuilt by using the electron density map improved by the solvent flatten and in accordance with the primary structure put forward by Collins. The crystallographic refinement of two trichosanthin molecules (3828 nonhydrogen atoms) in an asymmetric unit has been carried out by means of the restrain least-square procedure and diffraction data to a resolution of 2.6 A. The results are an R factor 0.223 and the r.m.s. deviation of the bond length = 0.023 A. The new molecular model is in good agreement with the electron density map calculated with the coefficient 2Fo-Fc.