Culebras E, Martínez J L, Baquero F, Pérez-Díaz J C
Centro Nacional de Biotecnología,(CSIC), Cantoblanco, Madrid, Spain.
J Antimicrob Chemother. 1996 May;37(5):881-9. doi: 10.1093/jac/37.5.881.
The kinetic constants of the aminoglycoside-modifying enzyme 6'-N-aminoglycoside acetyltransferase (AAC(6')IV) from the clinical strain Staphylococcus epidermidis RYC 13036 differed depending on whether tobramycin and amikacin (glycosamine group) or gentamicin and netilmicin (garosamine group) were used as substrates. Acetylation of the glucosamine antibiotics was highly susceptible to substrate inhibition which increased with pH whereas the garosamine group compounds showed limited substrate inhibition over a wide pH range. These differences in activity correlated with MIC values of S. epidermidis RYC 13036 for different aminoglycosides. Aminosugars moiety and pH markedly influenced the AAC(6')IV-aminoglycoside interactions.
来自临床菌株表皮葡萄球菌RYC 13036的氨基糖苷修饰酶6'-N-氨基糖苷乙酰基转移酶（AAC(6')IV）的动力学常数因将妥布霉素和阿米卡星（葡糖胺基团）或庆大霉素和奈替米星（加洛糖胺基团）用作底物而有所不同。葡糖胺抗生素的乙酰化对底物抑制高度敏感，且底物抑制随pH升高而增加，而加洛糖胺基团化合物在较宽的pH范围内显示出有限的底物抑制。这些活性差异与表皮葡萄球菌RYC 13036对不同氨基糖苷类药物的MIC值相关。氨基糖部分和pH显著影响AAC(6')IV与氨基糖苷之间的相互作用。
