Esquerra R M, Goldbeck R A, Kim-Shapiro D B, Kliger D S
Department of Chemistry and Biochemistry, University of California at Santa Cruz 95064, USA.
Biochemistry. 1998 Dec 15;37(50):17527-36. doi: 10.1021/bi9814437.
Nanosecond time-resolved absorption and magnetic optical rotatory dispersion (MORD) measurements of photolyzed myoglobin-CO visible bands (500-650 nm) are presented. These measurements reveal a 400 ns process, spectrally distinct from ligand recombination, that accounts for 7% of the observed spectral evolution in the visible absorption bands and 4% in the MORD. The time-resolved MORD, more sensitive to heme coordination geometry than absorption, suggests that this process is most likely associated with protein relaxation on the distal side of the heme pocket, perhaps accompanying rehydration of the deoxymyoglobin photoproduct or accommodation of protein side chains to ligand escape.
本文展示了对光解肌红蛋白-一氧化碳可见波段（500 - 650纳米）的纳秒时间分辨吸收和磁圆二色性（MORD）测量结果。这些测量揭示了一个400纳秒的过程，其光谱与配体重组不同，该过程占可见吸收波段中观察到的光谱演化的7%，在MORD中占4%。时间分辨MORD比吸收对血红素配位几何结构更敏感，这表明该过程很可能与血红素口袋远端的蛋白质弛豫有关，可能伴随着脱氧肌红蛋白光产物的再水化或蛋白质侧链对配体逸出的适应。
