FLUORESCENCE LIFETIME DISTRIBUTIONS IN PROTEINS
FLUORESCENCE LIFETIME DISTRIBUTIONS IN PROTEINS
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DOI：
10.1016/s0006-3495(87)83384-2
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发表时间：
1987-04-01
影响因子：
3.4
通讯作者：
PRENDERGAST, FG
中科院分区：
文献类型：
--
作者：
ALCALA, JR;GRATTON, E;PRENDERGAST, FG
色氨酸残基的荧光寿命值在不同蛋白质中变化超过100倍，并且由几个因素决定，包括溶剂暴露和与蛋白质基质的其他元素的相互作用。由于各种不同的元素可以改变色氨酸残基的寿命值和对特定环境的敏感性，因此很可能在蛋白质系统中产生非唯一的寿命值。大多数蛋白质的发射衰减仅用几个指数分量就能令人满意地描述。在这里，它提出了连续的寿命分布可以更好地代表所观察到的衰变。提出了一种基于蛋白质动力学的单色氨酸残基蛋白质荧光寿命分布函数的方法。首先，寿命分布的蛋白质相互转换的两种构象，每个特征在于不同的寿命值，推导。研究了寿命值随相互转化率的变化。在这种情况下，寿命分布可以从两种构象之间的相互转化率的分布中获得。第二，考虑了在给定构象内存在连续的能量亚态。在给定的温度下，特定的能量亚态的占据与玻尔兹曼因子成比例。势阱的能态密度取决于阱的宽度，这决定了残基在构象空间中移动的自由度。寿命分布可以通过将每个能量亚态与不同的寿命值相关联并假设平均构象可以随着亚态能量的增加而改变来获得。（250字处删节）
The fluorescence lifetime value of tryptophan residues varies by more than a factor of 100 in different proteins and is determined by several factors, which include solvent exposure and interactions with other elements of the protein matrix. Because of the variety of different elements that can alter the lifetime value and the sensitivity to the particular environment of the tryptophan residue, it is likely that non-unique lifetime values result in protein systems. The emission decay of most proteins can be satisfactorily described only using several exponential components. Here it is proposed that continuous lifetime distributions can better represent the observed decay. An approach based on protein dynamics is presented, which provides fluorescence lifetime distribution functions for single tryptophan residue proteins. First, lifetime distributions for proteins interconverting between two conformations, each characterized by a different lifetime value, are derived. The evolution of the lifetime values as a function of the interconversion rate is studied. In this case lifetime distributions can be obtained from a distribution of rates of interconversion between the two conformations. Second, the existence of a continuum of energy substates within a given conformation was considered. The occupation of a particular energy substate at a given temperature is proportional to the Boltzmann factor. The density of energy states of the potential well depends upon the width of the well, which determines the degree of freedom the residue can move in the conformational space. Lifetime distributions can be obtained by association of each energy substate with a different lifetime value and assuming that the average conformation can change as the energy of the substate is increased.(ABSTRACT TRUNCATED AT 250 WORDS)