Catanzano F, Graziano G, Cafaro V, D'Alessio G, Di Donato A, Barone G
Dipartimento di Chimica, Università di Napoli Federico II, Italy.
Int J Biol Macromol. 1998 Nov;23(4):277-85. doi: 10.1016/s0141-8130(98)00060-9.
Four residues Pro19. Leu28, Cys31 and Cys32 proved to be the minimal structural requirements in determining the dimeric structure and the N-terminal segment swapping of bovine seminal ribonuclease, BS-RNase. We analyzed the content of secondary and tertiary structures in RNase A, P-RNase A, PL-RNase A, MCAM-PLCC-RNase A and MCAM-BS-RNase, performing near and far-UV CD spectra. It results that the five proteins have very similar native conformations. Thermal denaturation at pH 5.0 of the proteins. studied by means of CD measurements. proved reversible and well represented by the two-state N<==>D transition model. Thermodynamic data are discussed in the light of the structural information available for RNase A and BS-RNase.
四个残基Pro19、Leu28、Cys31和Cys32被证明是决定牛精核糖核酸酶（BS-RNase）二聚体结构和N端片段交换的最小结构要求。我们通过近紫外和远紫外圆二色光谱分析了核糖核酸酶A、P-核糖核酸酶A、PL-核糖核酸酶A、MCAM-PLCC-核糖核酸酶A和MCAM-BS-核糖核酸酶的二级和三级结构含量。结果表明这五种蛋白质具有非常相似的天然构象。通过圆二色测量研究了这些蛋白质在pH 5.0时的热变性，结果证明是可逆的，并且可以很好地用两态N⇔D转变模型来表示。根据核糖核酸酶A和BS-核糖核酸酶的现有结构信息对热力学数据进行了讨论。
