Crystallization and preliminary X-ray analysis of cecropin B from Bombyx mori.
Cecropin B is a 37-residue cationic antimicrobial peptide derived from the haemolymph of Bombyx mori. The precise mechanism by which cecropins exert their antimicrobial and cytolytic activities is not well understood. Crystals of cecropin B were obtained by the hanging-drop vapour-diffusion method using polyethylene glycol as a precipitant at 289 K. The crystal diffracted to 1.43 A resolution using X-ray radiation and belonged to the orthorhombic space group P1, with unit-cell parameters a = 15.08, b = 22.75, c = 30.20 A, alpha = 96.9, beta = 103.1, gamma = 96.5 degrees. The asymmetric unit contained only one molecule of cecropin B, with a calculated Matthews coefficient of 2.48 A(3) Da(-1) and a solvent content of 50.4%.
Liu
Zhongyuan
Z
School of Medicine, Tsinghua University, Hai'dian District, Beijing 100084, People's Republic of China.
Zhou
Qiangjun
Q
Mao
Xinfang
X
Zheng
Xiangdong
X
Guo
Jiubiao
J
Zhang
Fuchun
F
Wen
Tingyi
T
Pang
Hai
H
D000818:Animals; D012831:Bombyx / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D019476:Insect Proteins / Q000737:chemistry*
D019476:Insect Proteins; C031162:cecropin B protein, Insecta