Conformational effects of nucleotide exchange in ras p21 proteins as studied by fluorescence spectroscopy

FEBS Letters

Neidle, Stephen³  Kuroda, Reiko³  Drake, Alex¹  Suter, David A.³  Hancock, John F.²  Skelly, Jane V.³ 

[1] Department of Chemistry, Birkbeck College, 20, Gordon Street, London WC1H OQB, England;Academic Department of Haematology, Royal Free Hospital, London NW3 2QG, England;CRC Biomolecular Structure Unit, Institute of Cancer Research, Sutton, Surrey SM2 5NG, England

关键词: p21 ras protein;    Guanine nucleotide binding;    Tryptophan fluorescence;   

DOI  :  10.1016/0014-5793(90)80170-N

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The intrinsic fluorescence properties of the oncogene protein p21^N-ras, p21^H-ras and one of its transforming mutants, p21^N-ras (Va1112), have been investigated. A mutant containing a single tryptophan at position 28 in p21^H-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.

【 授权许可】

Unknown