Rast D M, Bartnicki-Garcia S
Proc Natl Acad Sci U S A. 1981 Feb;78(2):1233-6. doi: 10.1073/pnas.78.2.1233.
The effects of amphotericin B (AmB), nystatin, filipin, and pimaricin were tested chitin synthase (EC 2.4.1.16) (chitosomes from yeast cells of Mucor rouxii). AmB and nystatin inhibited the enzyme at concentrations greater than or equal to 10 micrograms/ml, filipin was weakly inhibitory, and pimaricin had no effect. The inhibition of chitin synthase by AmB appears to be noncompetitive, with a Ki value of about 0.13 mM. the effect of nystatin was more complex and included a sharp stimulation of chitin synthase activity at approximately 50 micrograms/ml. Our findings suggest the existence of binding sites (sterols?) on the chitosome that are selective for certain polyenes and that play a role in the operation of chitin synthase. Because the minimal growth inhibitory concentrations of AmB or nystatin are lower than the concentrations that inhibit chitin synthase in vitro, the possibility of chitosomal chitin synthase being a primary target for the antifungal action of these polyenes seems unlikely.
测试了两性霉素B（AmB）、制霉菌素、菲律宾菌素和匹马菌素对几丁质合酶（EC 2.4.1.16）（来自鲁氏毛霉酵母细胞的几丁质体）的作用。AmB和制霉菌素在浓度大于或等于10微克/毫升时抑制该酶，菲律宾菌素的抑制作用较弱，而匹马菌素无作用。AmB对几丁质合酶的抑制作用似乎是非竞争性的，其Ki值约为0.13毫摩尔。制霉菌素的作用更为复杂，包括在约50微克/毫升时对几丁质合酶活性的急剧刺激。我们的研究结果表明，几丁质体上存在对某些多烯具有选择性的结合位点（固醇？），并且这些位点在几丁质合酶的运作中发挥作用。由于AmB或制霉菌素的最低生长抑制浓度低于体外抑制几丁质合酶的浓度，几丁质体几丁质合酶作为这些多烯抗真菌作用的主要靶点的可能性似乎不大。
