仿生信号转导系统中的化学振荡:囊泡表面引入DPIP后诱发的机械-光信号转换

摘要

在一个已构建的以细胞肌醇磷脂信号转导途径为原型的仿生信号转导系统中,处于合成肽脂质囊泡表面的乳酸脱氢酶LDH被激活后,催化乳酸脱氢反应过程中,使辅酶NADH氧化为NAD,在此过程中引入DPIP.利用DPIP,在囊泡表面形成了一个由机械信号到光信号转换的化学振荡体系,该体系以DPIP和NADH摩尔比为1∶10的比例进行振荡,其平均循环周期为32min,大于无肽脂质囊泡存在的体系之平均循环周期时间.结果表明:囊泡表面引入DPIP后,在整个系统受到机械刺激信号时,可以引发一个溶液从蓝色到无色,再由无色到蓝色,循环往复的化学振荡.由于LDH结合在囊泡表面,这可能降低了其对NADH的活化作用,从而令化学振荡的平均循环周期时间加长.%In a constructed artificial signal transduction system,which was inspired by the biological phosphoinositide(PI)-triggered signal transduction,2,6-dichlorophenolindophenol (DPIP)was introduced into the process of the lactic acid catalyzed by Lactate dehydrogenase,simultaneously,the coenzyme NADH was oxidated to NAD+.DPIP was utilized on the vesicles to translate a mechanical signal to an optical output for use as a chemical oscillatory reaction.The system was studied with UV-vis 2450 spectrometer and the average period of system was 32 rain when DPIP ∶ NADH was 1 ∶ 10(mole ratio),longer than that of system without bilayer vesicles.The results indicated that the catalysis of enzyme would be reduced because of the combination between the enzyme and the bilayer vesicles.