ROTATIONAL FREEDOM OF TRYPTOPHAN RESIDUES IN PROTEINS AND PEPTIDES
ROTATIONAL FREEDOM OF TRYPTOPHAN RESIDUES IN PROTEINS AND PEPTIDES
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DOI：
10.1021/bi00277a001
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发表时间：
1983-01-01
期刊：
影响因子：
2.9
通讯作者：
BALTER, A
中科院分区：
文献类型：
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作者：
LAKOWICZ, JR;MALIWAL, BP;BALTER, A
通过测定蛋白质和多肽中色氨酸残基在氧猝灭条件下的稳态荧光各向异性，研究了色氨酸残基的旋转运动。通过荧光猝灭，可以缩短荧光寿命，从而减少在荧光发射之前用于旋转扩散的平均时间。这种方法允许测量的旋转相关时间范围从0.03-50 ns，当未淬灭的荧光寿命是近4 ns。研究了MW范围为200- 80，000的各种蛋白质和肽。许多选定的物质具有一个单一的色氨酸残基，以尽量减少由荧光团的异质性人口所产生的不确定性。此外，还研究了许多多色氨酸蛋白。在各种温度下，在自缔合的条件下，并在变性剂的存在下，蛋白质进行了研究。作为例子，单个色氨酸残基的髓鞘碱性蛋白是高度移动的相对于整体蛋白质旋转，而色氨酸残基在人血清白蛋白，核糖核酸酶T1，醛缩酶和马肝醇脱氢酶是im移动的相对于蛋白质基质。人们不能概括蛋白质中色氨酸残基的链段移动程度。蛋白质的这种物理性质在蛋白质之间以及可能在同一蛋白质的不同区域之间高度可变。
The rotational motions of tryptophan residues in proteins and peptides were studied by measurement of steady-state fluoresence anisotropies under conditions of O2 quenching. By fluorescence quenching the fluorescence lifetime can be shortened thereby decreasing the average time for rotational diffusion prior to fluorescence emission. This method allowed measurement of rotational correlation times ranging from 0.03-50 ns, when the unquenched fluorescence lifetimes are near 4 ns. A wide range of proteins and peptides were investigated with MW ranging from 200-80,000. Many of the chosen substances possessed a single tryptophan residue to minimize the uncertainties arising from a heterogeneous population of fluorophores. In addition a number of multi-tryptophan proteins were also studied. Proteins were studied at various temperatures, under conditions of self-association, and in the presence of denaturants. A wide variety of rotational correlation times were found. As examples, the single tryptophan residue of myelin basic protein was highly mobile relative to overall protein rotation whereas tryptophan residues in human serum albumin, RNase T1, aldolase and horse liver alcohol dehydrogenase were immobile relative to the protein matrix. One cannot generalize about the extent of segmental mobility of the tryptophan residues in proteins. This physical property of proteins is highly variable between proteins and probably between different regions of the same protein.