CAJ | 학술논문

肌红蛋白(Myoglobin，Mb)中血红素辅基不仅具有储氧功能，也能吸收特定波长的光而影响蛋白功能表达。实验发现，部分游离的氨基酸对光诱导高铁肌红蛋白(metMb，Fe(III)-Mb)的还原过程及还原程度都有重要作用，因此，本文采用紫外-可见吸收光谱、圆二色谱、三维荧光光谱法，在光照体系中加入拥挤试剂来模拟细胞内拥挤环境，研究芳香氨基酸[色氨酸(Trp)、苯丙氨酸(Phe)、酪氨酸(Tyr)、半胱氨酸(Cys)]对metMb还原的影响。结果表明，含-OH或-SH的氨基酸(Tyr、Cys)能使metMb发生较好的光还原，无-OH或-SH基团的氨基酸(Trp、Phe)对metMb的光还原作用较弱，氨基酸促进metMb光还原的整个过程可能是分子间电子转移的过程。metMb在拥挤环境聚蔗糖70(Ficoll 70)中的光诱导还原程度比在稀溶液中高，拥挤试剂Ficoll70对蛋白的二级结构起保护作用，能够稳定血红素微环境。
기홍단백(Myoglobin，Mb)중혈홍소보기불부구유저양공능，야능흡수특정파장적광이영향단백공능표체。실험발현，부분유리적안기산대광유도고철기홍단백(metMb，Fe(III)-Mb)적환원과정급환원정도도유중요작용，인차，본문채용자외-가견흡수광보、원이색보、삼유형광광보법，재광조체계중가입옹제시제래모의세포내옹제배경，연구방향안기산[색안산(Trp)、분병안산(Phe)、락안산(Tyr)、반광안산(Cys)]대metMb환원적영향。결과표명，함-OH혹-SH적안기산(Tyr、Cys)능사metMb발생교호적광환원，무-OH혹-SH기단적안기산(Trp、Phe)대metMb적광환원작용교약，안기산촉진metMb광환원적정개과정가능시분자간전자전이적과정。metMb재옹제배경취자당70(Ficoll 70)중적광유도환원정도비재희용액중고，옹제시제Ficoll70대단백적이급결구기보호작용，능구은정혈홍소미배경。
Myoglobin heme cofactor can absorb specific wavelength of light to affect the expression of protein function. In this work, we found free amino acid plays an important role in photoreduction of met-myoglobin. The influence of aromatic amino acids (tryptophan, phenylalanine and tyrosine) and cysteine on the photoreduction of myoglobin in the crowded environment by adding crowded reagents is studied by UV-Vis absorption, CD spectra and three-dimensional fluorescence spectroscopy. The UV-Vis absorption data revealed that the amino acids containing -OH or -SH groups (Tyr, Cys) can facilitate the photoreduction process of Mb, while the amino acids without-OH or-SH groups (Trp, Phe) have weakly effect on photoreduction of Mb. The photoreduction process of Mb promoted by amino acids may be radical electron transfer process. The photoreduction extent of metMb is much higher in Ficoll70 solution than that in dilute solution. In addition, crowded reagent Ficoll70 can protect the secondary structure of protein and stabilize the heme microenvironment.