Skelly J V, Suter D A, Kuroda R, Neidle S, Hancock J F, Drake A
CRC Biomolecular Structure Unit, Institute of Cancer Research, Sutton, Surrey, England.
FEBS Lett. 1990 Mar 12;262(1):127-30. doi: 10.1016/0014-5793(90)80170-n.
The intrinsic fluorescence properties of the oncogene protein p21N-ras,p21H-ras and one of its transforming mutants, p21N-ras (Val12), have been investigated. A mutant containing a single tryptophan at position 28 in p21H-ras (Trp28) has been specifically engineered to provide a probe of protein conformation on nucleotide binding. The proteins produced essentially similar circular dichroism spectra typical of alpha/beta proteins. A decrease in the intensity of the fluorescence emission spectrum due to tyrosine occurred on GDP/GTP nucleotide exchange in the native and mutant proteins. Selective excitation of the single tryptophan in p21 produced a decrease in fluorescence intensity which was accompanied by a blue shift in the wavelength of maximum emission on nucleotide exchange. A reduction in the residual Mg2+ ion concentration enhanced this effect.
对癌基因蛋白p21N-ras、p21H-ras及其一种转化突变体p21N-ras（Val12）的固有荧光特性进行了研究。已专门构建了一种在p21H-ras第28位含有单个色氨酸的突变体（Trp28），以提供核苷酸结合时蛋白质构象的探针。这些蛋白质产生了本质上相似的典型α/β蛋白质的圆二色光谱。在天然和突变蛋白质中，由于酪氨酸导致的荧光发射光谱强度在GDP/GTP核苷酸交换时降低。对p21中单个色氨酸的选择性激发导致荧光强度降低，同时在核苷酸交换时最大发射波长发生蓝移。残余Mg2+离子浓度的降低增强了这种效应。
