Esfahani M, Devlin T M
J Biol Chem. 1982 Sep 10;257(17):9919-21.
Fluorescence characteristics of tryptophan residues in yeast plasma membrane indicate that the residues are buried. The fluorescence is fully quenchable by iodide with similar quenching kinetics at temperatures from 8 to 37 degrees C in oleate-enriched membranes and from 25 to 37 degrees C in palmitelaidate-enriched membranes. Substantial increases in lipid microviscosity in palmitelaidate-enriched membranes reduce the fraction of quenchable tryptophan fluorescence by about 40% and increase the effective quenching constant 3-fold. These observations indicate that at above 25 degrees C, proteins in this membrane undergo transient conformational changes and that freedom of conformational changes of the proteins is regulated by lipid microviscosity.
酵母质膜中色氨酸残基的荧光特性表明这些残基被埋藏。在富含油酸的膜中，温度在8至37摄氏度时，以及在富含棕榈油酸的膜中，温度在25至37摄氏度时，碘化物可完全淬灭荧光，且淬灭动力学相似。富含棕榈油酸的膜中脂质微粘度的显著增加使可淬灭色氨酸荧光的比例降低约40%，并使有效淬灭常数增加3倍。这些观察结果表明，在25摄氏度以上，该膜中的蛋白质会发生瞬时构象变化，并且蛋白质构象变化的自由度受脂质微粘度调节。
