Sommer J H, Henry E R, Hofrichter J
Biochemistry. 1985 Dec 3;24(25):7380-8. doi: 10.1021/bi00346a053.
Transient optical absorption spectra of myoglobin were measured following photolysis of the n-butyl isocyanide complex with 10-ns laser pulses at room temperature. The data were analyzed by using singular value decomposition to give the kinetics of ligand rebinding and spectral changes. Geminate recombination phases were observed at 30 ns and 1 microsecond following photodissociation. These processes were accompanied by simultaneous changes in the shape of the Soret band which indicate changes in protein conformation. These spectral changes are not present in the geminate recombination of photolyzed complexes of myoglobin with the diatomic ligands oxygen and carbon monoxide. This difference in behavior, as well as the slower overall association rate of n-butyl isocyanide to myoglobin, can be rationalized as arising from distortion of the protein structure by the larger isocyanide ligand along the binding pathway.
在室温下用10纳秒激光脉冲光解正丁基异氰化物配合物后，测量了肌红蛋白的瞬态光吸收光谱。通过奇异值分解分析数据，以给出配体重新结合的动力学和光谱变化。在光解离后的30纳秒和1微秒观察到双生复合相。这些过程伴随着Soret带形状的同时变化，这表明蛋白质构象发生了变化。在肌红蛋白与双原子配体氧气和一氧化碳的光解配合物的双生复合中不存在这些光谱变化。这种行为差异，以及正丁基异氰化物与肌红蛋白的整体缔合速率较慢，可以解释为是由于较大的异氰化物配体沿结合途径使蛋白质结构发生扭曲所致。
