Shinkarev Vladimir P
Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Biophys J. 2005 Jan;88(1):412-21. doi: 10.1529/biophysj.104.050898. Epub 2004 Oct 8.
Flash-induced oxygen evolution in higher plants, algae, and cyanobacteria exhibits damped period-four oscillations. To explain such oscillations, Kok suggested a simple phenomenological S-state model, in which damping is due to empirical misses and double-hits. Here we developed an analytical solution for the extended Kok model that includes misses, double-hits, inactivation, and backward-transitions. The solution of the classic Kok model (with misses and double-hits only) can be obtained as a particular case of this solution. Simple equations describing the flash-number dependence of individual S-states and oxygen evolution in both cases are almost identical and, therefore, the classic Kok model does not have a significant advantage in its simplicity over the extended version considered in this article. Developed equations significantly simplify the fitting of experimental data via standard nonlinear regression analysis and make unnecessary the use of many previously developed methods for finding parameters of the model. The extended Kok model considered here can provide additional insight into the effect of dark relaxation between flashes and inactivation.
高等植物、藻类和蓝细菌中闪光诱导的氧气释放呈现出阻尼的四周期振荡。为了解释这种振荡，科克提出了一个简单的唯象S态模型，其中阻尼是由于经验性遗漏和双击中。在这里，我们为扩展的科克模型开发了一个解析解，该模型包括遗漏、双击中、失活和反向转换。经典科克模型（仅包含遗漏和双击中）的解可以作为该解的一个特殊情况得到。描述两种情况下单个S态和氧气释放对闪光次数依赖性的简单方程几乎相同，因此，经典科克模型在简单性方面并不比本文所考虑的扩展版本具有显著优势。所推导的方程通过标准非线性回归分析显著简化了实验数据的拟合，并且不再需要使用许多先前开发的用于寻找模型参数的方法。这里所考虑的扩展科克模型可以为闪光之间的暗弛豫和失活的影响提供额外的见解。
