First order decay rate constant of pyridoxal-P cofactor after excitation with 470 nm laser

Value 152000 1/sec
Organism Unspecified
Reference Martin SM, Lindroth JR, Ledbetter JW. Protein dynamics of glycogen phosphorylase. Biochemistry. 1986 Oct 7 25(20):6070-6PubMed ID3098284
Primary Source Cornish TJ, Ledbetter JW. Interactions at the active site of glycogen phosphorylase b. A new laser probe. Eur J Biochem. 1984 Aug 15 143(1):63-7PubMed ID6432537
Method Flash excitation
Comments The enol structure of the pyridoxal-P cofactor of glycogen phosphorylase absorbs well the 337-nm emission of the nitrogen laser. When excited, the cofactor exhibits a transient absorption at about 470 nm (Walters et al., 1982 Cornish & Ledbetter, 1984a). Cornish and Ledbetter (1984a) describe the absorption decay as the sum of two exponentials: a strong first-order decay with a rate constant of 1.52 X E5 s^-1 and a weak slowly decaying tail with a rate constant of 5.74 X E3 Sec^-1. The source of the strong fast decay is an excited singlet state with the 3-OH proton of pyridoxal on the imine nitrogen of the Schiff base linkage. See BNID 104763
Entered by Uri M
ID 104762