Mezyk S P
Radiation Laboratory, University of Notre Dame, Indiana 46556, USA.
Radiat Res. 1996 Jan;145(1):102-6.
The techniques of pulse radiolysis and absorption spectroscopy have been used to determine absolute rate constants for the reaction of hydroxyl and oxide radicals with cysteine (CysS) species in aqueous solution. Using measured equilibrium constants for radical disulfide anion formation, over the pH range 6.0-13.0, observed reaction rate constants were resolved into their constituent reactions .OH + CysSH-->H2O + CysS. and .O(-) + CysS-( + H2O)-->CysS. + 2OH- with calculated limiting rate constants of (5.35 +/- 0.82) x 10(9) and (3.28 +/- 0.49) x 10(8) dm3 mol-1 s-1, respectively. The rate constant for hydroxyl radical reaction with CysS- was found to be the same as that for CysSH.
脉冲辐解和吸收光谱技术已被用于测定水溶液中羟基自由基和氧自由基与半胱氨酸（CysS）物种反应的绝对速率常数。利用测得的自由基二硫阴离子形成的平衡常数，在pH值6.0 - 13.0范围内，将观察到的反应速率常数分解为其组成反应：.OH + CysSH→H₂O + CysS. 和.O⁻ + CysS⁻( + H₂O)→CysS. + 2OH⁻，计算得到的极限速率常数分别为(5.35 ± 0.82)×10⁹和(3.28 ± 0.49)×10⁸ dm³ mol⁻¹ s⁻¹。发现羟基自由基与CysS⁻反应的速率常数与与CysSH反应的速率常数相同。
