Picard B, Philippe J C, Goullet P
Laboratoire de Microbiologie, Faculté de Médecine Xavier Bichat (Université Paris VII), France.
Biochem Genet. 1990 Feb;28(1-2):69-81. doi: 10.1007/BF00554822.
The high levels of electrophoretic polymorphism of esterase M detected in eight distinct hybridization groups of motile Aeromonas raise questions of genetic homogeneity of the electromorphs. The 40 electromorphs detected fall in four Mr classes--75, 80, 90, and 110 kD--and one typical variant belonging to each of these classes was purified. The four purified esterases exhibited the same resistance to heat, to pH and to diisopropyl fluorophosphate, the same Km values for 1-naphthyl acetate and 1-naphthyl propionate (1 mM), and immunological cross-reactions. Within each class, the electromorphs appeared to be related in term of single amino acid substitutions as estimated from their comparative titration patterns. The titration curves of the four purified esterases were strictly parallel suggesting close structural similarities. Thus, despite considerable variation in their pI, MF, and Mr values, it seems likely that the variants of esterase M are the products of closely related loci originating from a common ancestral gene.
在运动性气单胞菌的八个不同杂交组中检测到的酯酶M的高电泳多态性，引发了对电变体遗传同质性的质疑。检测到的40种电变体分为四个分子量类别——75、80、90和110 kD——并且纯化了每个类别中的一个典型变体。这四种纯化的酯酶对热、pH和二异丙基氟磷酸表现出相同的抗性，对1-萘乙酸和1-萘丙酸（1 mM）具有相同的Km值，并且存在免疫交叉反应。在每个类别中，根据其比较滴定模式估计，电变体似乎是由单个氨基酸取代相关联的。四种纯化酯酶的滴定曲线严格平行，表明结构相似性很高。因此，尽管它们的pI、MF和分子量值存在相当大的差异，但酯酶M的变体似乎很可能是源自共同祖先基因的密切相关基因座的产物。
