Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706.
Infect Immun. 1970 Jan;1(1):109-19. doi: 10.1128/iai.1.1.109-119.1970.
A resistance (R) factor- containing strain of Escherichia coli which is known to inactivate streptomycin by adenylylation has been shown to be spectinomycin resistant. An osmotic shockate of this strain catalyzes the formation of the biologically inactive spectinomycin adenylate, in which the adenylyl residue is probably attached to a d-threo methylamino alcohol moiety of spectinomycin. Both the streptomycin and spectinomycin adenylylating activities show the same temperature inactivation profile, and both are present in a protein fraction purified for the streptomycin inactivating enzyme. Mutants obtained from this strain which were sensitive to either spectinomycin or streptomycin were shown to lack both enzymatic activities when tested in vitro. Revertants of these mutants selected for recovery of either streptomycin resistance or spectinomycin resistance regain both activities. Therefore, we conclude that the inactivation of the two drugs is catalyzed by the same enzyme. Examination of a number of R factor-carrying strains has shown that those strains which are resistant to streptomycin and spectinomycin contain the adenylylating enzyme, whereas strains resistant to streptomycin but sensitive to spectinomycin inactivate streptomycin by phosphorylation.
一株含有耐药因子的大肠杆菌菌株，该因子通过腺苷酸化使链霉素失活，现已证明其对壮观霉素具有耐药性。该菌株的渗透压休克液催化形成生物活性降低的壮观霉素腺苷酸，其中腺苷酰基残基可能连接到壮观霉素的 d-苏糖醇基氨基醇部分。链霉素和壮观霉素的腺苷酰化活性都具有相同的温度失活动力学，并且都存在于为失活链霉素酶而纯化的蛋白质部分中。从该菌株获得的对链霉素或壮观霉素敏感的突变体在体外试验中均缺乏这两种酶活性。这些突变体的回复突变体选择恢复链霉素或壮观霉素耐药性时，均可恢复这两种活性。因此，我们得出结论，两种药物的失活是由相同的酶催化的。对许多带有 R 因子的菌株进行检查表明，那些对链霉素和壮观霉素都具有耐药性的菌株含有腺苷酰化酶，而对链霉素耐药但对壮观霉素敏感的菌株则通过磷酸化使链霉素失活。
