Verma M, Siddiqui J Z
Biochem Int. 1986 Feb;12(2):267-77.
Bacteriophage 9NA is a virulent phage of Salmonella typhimurium which induces a lysozyme in host cells toward the later stages of its multiplication. 9NA lysozyme has been purified about 1000 fold starting from the lysate of 9NA infected cells. The enzyme has an optimum pH between 7 and 8 and its activity is dependent on the ionic strength of the assay medium. Salts like NaCl and KCl are inhibitory to the lysozyme. Gram-negative cells act as better substrate for the lysozyme than do Gram-positive cells. The enzyme has a molecular weight of about 2.1 X 10(4) and rapidly loses its activity at temperatures higher than 45 degrees C. The properties of 9NA lysozyme have been compared with those of T4, lambda and P22 lysozymes.
噬菌体9NA是鼠伤寒沙门氏菌的一种烈性噬菌体，在其增殖后期可诱导宿主细胞产生溶菌酶。从9NA感染细胞的裂解物开始，9NA溶菌酶已被纯化了约1000倍。该酶的最适pH在7至8之间，其活性取决于测定介质的离子强度。像氯化钠和氯化钾这样的盐对溶菌酶有抑制作用。革兰氏阴性细胞比革兰氏阳性细胞更适合作为溶菌酶的底物。该酶的分子量约为2.1×10⁴，在高于45℃的温度下会迅速失去活性。已将9NA溶菌酶的特性与T4、λ和P22溶菌酶的特性进行了比较。
