Acta Phys. -Chim. Sin. ›› 2009, Vol. 25 ›› Issue (01): 25-29.doi: 10.3866/PKU.WHXB20090105

• ARTICLE • Previous Articles     Next Articles

Photodamage and Photooxidation Mechanisms of Bovine Serum Albumin

CHENG Ling-Li; ZHAO Ping; WANG Mei; ZHU Hui; ZHU Rong-Rong; SUN Xiao-Yu; WANG Shi-Long   

  1. School of Life Science and Technology, Tongji University, Shanghai 200092, P. R. China
  • Received:1900-01-01 Revised:1900-01-01 Published:2008-12-31
  • Contact: WANG Shi-Long

Abstract: Photodamage and photooxidation mechanisms of bovine serumalbumin (BSA) as induced by UVradiation
and one-electron oxidation by SO4-· were investigated by 266 nm laser flash photolysis. BSA can be photoionized and photoexcited by 266 nm photons to give tryptophan (Trp)/NH+·, Trp/N· resulting from the rapid deprotonation of Trp/NH+·, and 3Trp*. Through intermolecular electron transfer between 3Trp* and tyrosine (Tyr), Tyr/O· was produced. In one-electron oxidation of BSA by SO4-· the apparent set up rate constants of Tyr and Trp radicals were calculated but intermolecular electron transfer was not observed. We propose that SO4-· oxidizes BSA by electron transfer to the Tyr and Trp of BSA with a rate constant of 1.51×1010 L·mol-1·s-1. This research provides an introductory theory to enable further study on the redox metabolic process of BSA.

Key words: Bovine serumalbumin, Photo-ionization, Photo-excitation, Electron transfer, One-electron oxidization


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