Cao HY, Ma YQ, Gao LX, Tang Q, Zheng XF. Photo induced reaction of myoglobins with energy transferred from excited free tryptophan.
RSC Adv 2020;
10:43853-43858. [PMID:
35519687 PMCID:
PMC9058398 DOI:
10.1039/d0ra09341f]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 11/24/2020] [Indexed: 01/05/2023] Open
Abstract
Despite being one of the most studied proteins in biology, the photolysis mechanism of myoglobin heme affected by endogenous substances free amino acids is still in controversy. The transient absorption and kinetic processes of photo-excited myoglobin in three forms and the effects of free excited tryptophan on redox reaction of myoglobin were monitored by laser flash photolysis. With dual energy superposition of direct light irradiation and indirect energy transferred from the free excited tryptophan, the variation value in optical density (ΔOD) of MetMb increased by 66.7%, from 0.9 to 1.5. The ΔOD value of MbO2 in ferrous form increased from 0.9 to 1.25, while the ΔOD value of DeoxyMb increased from 0.75 to 1.2. The decay time of excited DeoxyMb was prolonged obviously with the excited tryptophan, while the decay time of excited MbO2 and MetMb was shortened significantly. The excited tryptophan could promote laser induced reaction processes of myoglobin in different forms by intermolecular energy transfer to one final similar photo reaction state. The possible photo induced reaction mechanisms of DeoxyMb, MbO2, MetMb with and without free tryptophan were also proposed.
The dual energy superposition of direct light irradiation and indirect energy transferred from the free excited tryptophan promoted the photo induced reaction of myoglobin.![]()
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