Taylor B E, Irvin J D
Department of Chemistry, Southwest Texas State University, San Marcos 78666.
FEBS Lett. 1990 Oct 29;273(1-2):144-6. doi: 10.1016/0014-5793(90)81070-5.
Mammalian ribosomes have been shown to be enzymatically modified by ribosomal inactivating protein (RIPs) via specific depurination of rRNA. Here we report that ribosomes isolated from wheat germ contain intact and undepurinated rRNA and are depurinated by pokeweed antiviral protein (PAP). Pokeweed ribosomes isolated under the same conditions are depurinated. Total RNA isolated from pokeweed in the presence of strong denaturants was found to pbe partially depurinated. We conclude that wheat germ ribosomes are resistant to the endogenous RIP, tritin, but are sensitive to PAP and that pokeweed ribosomes can be depurinated by the N-glycosidase activity of endogenous PAP during isolation.
哺乳动物核糖体已被证明会通过核糖体失活蛋白（RIPs）对rRNA进行特异性脱嘌呤作用而发生酶促修饰。在此我们报告，从小麦胚芽中分离出的核糖体含有完整且未脱嘌呤的rRNA，并会被商陆抗病毒蛋白（PAP）脱嘌呤。在相同条件下分离出的商陆核糖体也会被脱嘌呤。在强变性剂存在的情况下从小麦中分离出的总RNA被发现部分脱嘌呤。我们得出结论，小麦胚芽核糖体对内源RIP、tritin具有抗性，但对PAP敏感，并且商陆核糖体在分离过程中会被内源性PAP的N-糖苷酶活性脱嘌呤。
