Long-lived amide I vibrational modes in myoglobin.
Pump-probe experiments in the infrared measure vibrational relaxation rates. Myoglobin, which is almost entirely alpha helix in secondary structure, has an unusually long, nonexponential excited state relaxation generated by optically pumping at the blue side ( 5. 85 microm) of the amide I band. The amino acid alanine and the predominantly beta sheet protein photoactive yellow protein do not have such a long-lived state, suggesting that the alpha helix in proteins can support nonlinear states of 15 ps characteristic times.
Xie
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Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74708, USA.
van Der Meer
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Hoff
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Austin
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D000577:Amides / Q000737:chemistry*; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry; D007700:Kinetics; D007834:Lasers; D008958:Models, Molecular; D009211:Myoglobin / Q000737:chemistry*; D020283:Photoreceptors, Microbial; D017433:Protein Structure, Secondary; D013055:Spectrophotometry, Infrared; D014732:Vibration; D014907:Whales
D000577:Amides; D001426:Bacterial Proteins; D009211:Myoglobin; D020283:Photoreceptors, Microbial; C050162:photoactive yellow protein, Bacteria