Ito Y, Kwon O H, Ueda M, Tanaka A, Imanishi Y
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Japan.
FEBS Lett. 1997 Oct 6;415(3):285-8. doi: 10.1016/s0014-5793(97)01140-x.
The amphiphilic polypeptide polyproline having different chain lengths was connected to the C-terminus of human lysozyme by the recombinant DNA technique. The hydrophobicity of human lysozyme increased with increasing length of the polyproline chain. Although the bactericidal activity of wild-type lysozyme is limited to gram-positive bacteria and the hydrolytic activity of the mutant lysozyme decreased with increasing chain length of polyproline, the mutant lysozymes showed bactericidal activity to gram-negative bacteria and the activity increased with increasing hydrophobicity of the mutant enzyme. Experiments with Escherichia coli phospholipid liposomes revealed that the mutant human lysozymes dissipated the valinomycin-induced transmembrane electrochemical potential, and the dissipation increased with increasing hydrophobicity. The increased hydrophobicity of the mutant enzyme may induce interaction of lysozyme with the outer membrane and subsequent penetration into the inner membrane of E. coli, resulting in an increase of bactericidal activity.
通过重组DNA技术将具有不同链长的两亲性多肽聚脯氨酸连接到人溶菌酶的C末端。人溶菌酶的疏水性随着聚脯氨酸链长度的增加而增加。虽然野生型溶菌酶的杀菌活性仅限于革兰氏阳性菌，且突变型溶菌酶的水解活性随着聚脯氨酸链长度的增加而降低，但突变型溶菌酶对革兰氏阴性菌表现出杀菌活性，且该活性随着突变酶疏水性的增加而增强。对大肠杆菌磷脂脂质体的实验表明，突变型人溶菌酶消除了缬氨霉素诱导的跨膜电化学势，且这种消除随着疏水性的增加而增强。突变酶疏水性的增加可能诱导溶菌酶与外膜相互作用，并随后穿透到大肠杆菌的内膜，从而导致杀菌活性增加。
