Libonati M, Bertoldi M, Sorrentino S
Istituto di Chimica Biologica, Facoltà di Medicine e Chirurgla, Università di Verona, Italy.
Biochem J. 1996 Aug 15;318 ( Pt 1)(Pt 1):287-90. doi: 10.1042/bj3180287.
Stable bovine RNase A aggregates larger than dimers (identified as trimers, tetramers, pentamers and hexamers) were obtained by lyophilization of RNase A from 40-50% acetic acid solutions. The RNase activity of these aggregates was compared with that of monomeric RNase A on single- and double-stranded polyribonucleotides. Their activity toward poly(U) and yeast RNA slightly decreases as a function of the size of the aggregates. In contrast, their action on poly(A).poly(U) as substrate progressively increases from a relative activity of 1 for the RNase monomer to 10 for the hexamer. These results are discussed in the light of an already advanced hypothesis about a possible mechanism of RNase attack on double-stranded RNA.
通过对40%-50%醋酸溶液中的核糖核酸酶A进行冻干，获得了大于二聚体的稳定牛核糖核酸酶A聚集体（鉴定为三聚体、四聚体、五聚体和六聚体）。将这些聚集体的核糖核酸酶活性与单体核糖核酸酶A对单链和双链多核糖核苷酸的活性进行了比较。它们对聚（U）和酵母RNA的活性随聚集体大小的增加而略有降低。相反，它们以聚（A）·聚（U）为底物的活性从核糖核酸酶单体的相对活性1逐渐增加到六聚体的10。根据关于核糖核酸酶攻击双链RNA可能机制的一个已提出的假设对这些结果进行了讨论。
