期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1973
卷号:70
期号:11
页码:3141-3144
DOI:10.1073/pnas.70.11.3141
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:We report results of the application of the "pulse method" to the study of photodissociation of various ligands from several heme proteins. By use of this technique, which allows the determination of the quantum yield of photodissociation accurately and rapidly, several ligands (CO, O2, isocyanides) have been investigated for sperm-whale myoglobin and trout hemoglobin I. In agreement with previous results, the new data lead to the conclusion that no simple relationship exists between the quantum yield and the affinity constant in the ground state. For trout hemoglobin I, the experiments were extended to measure the quantum yield of the CO photodissociation as a function of the initial degree of saturation, from fully saturated down to the initial values of about 1.5%. The results yield additional information to that obtained by the "steady-state" method, and in particular exclude the idea that the photochemical yield is in any way dependent on the fractional saturation of the molecule with carbon monoxide.
关键词:photodissociation ; sperm-whale myoglobin ; trout hemoglobin I