Winkler M H
Montefiore Hospital and Medical Center, Bronx, New York, and the Protein Foundation, Boston, Massachusetts, USA.
Biophys J. 1967 Nov;7(6):719-25. doi: 10.1016/S0006-3495(67)86618-9. Epub 2008 Dec 31.
The fluorescent emission spectra for 5 x 10(-6) M p-aminohippuric and p-aminobenzoic acids in mixtures of methyl alcohol and 1,2-propanediol have been determined. The results indicate that at almost invariant dielectric constant the quantum yield of fluorescence is a function of the viscosity of the solvent. The suggestion is made that a collisional quenching mechanism, which involves the rotational diffusion of solvent molecules, is significant in solutions of low viscosity and less so at high viscosities. A prediction, on the basis of the proposed mechanism, of augmentation of the emission spectra of p-aminohippuric acid, after binding to homologous antihapten antibody, is confirmed. A small red shift is also noted at higher viscosities in protein-free solutions or after binding to homologous antibody. It is suggested that, contrary to some interpretations in the literature, a red shift and/or an augmentation of quantum yield of fluorescence may, in specific instances, not be significant of a transfer of the fluorochrome to an environment of lower dielectric constant.
已测定了5×10⁻⁶ M对氨基马尿酸和对氨基苯甲酸在甲醇与1,2 -丙二醇混合物中的荧光发射光谱。结果表明，在几乎不变的介电常数下，荧光量子产率是溶剂粘度的函数。有人提出，一种涉及溶剂分子旋转扩散的碰撞猝灭机制在低粘度溶液中很重要，而在高粘度溶液中则不太重要。基于所提出的机制，对氨基马尿酸与同源抗半抗原抗体结合后发射光谱增强的预测得到了证实。在无蛋白溶液中或与同源抗体结合后，在较高粘度下也观察到了小的红移。有人认为，与文献中的一些解释相反，在特定情况下，荧光红移和/或量子产率的增加可能并不意味着荧光团转移到了介电常数较低的环境中。
