Nakatani H, Hiromi K
Biochim Biophys Acta. 1978 Jun 9;524(2):413-7. doi: 10.1016/0005-2744(78)90178-x.
m-Nitrobenzeneboronic acid as a possible transition-state analog for serine proteases was found to cause absorption spectral change from 250 nm 350 nm upon binding with subtilisin BPN' (EC 3.4.21.14) at pH 6.5. Similar difference spectral changes of m-nitrobenzeneboronic acid were also observed at alkaline pH or upon addition of N-methylimidazole at pH 6.5. A characteristic circular dichroism spectrum of m-nitrobenezeneboronic acid was induced upon binding with subtilisin BPN' not only at pH 6.5, but also at alkaline pH. Circular dichroism spectral titration confirmed the stoichiometry of 1 : 1 for the m-nitrobenzeneboronic acid - subtilisin complex. m-Nitrobenzeneboronic acid was shown to be useful as a reversible chromophoric probe for the catalytic site of serine proteases.
间硝基苯硼酸作为丝氨酸蛋白酶可能的过渡态类似物，发现在pH 6.5条件下与枯草杆菌蛋白酶BPN'（EC 3.4.21.14）结合时会引起吸收光谱从250纳米到350纳米的变化。在碱性pH条件下或在pH 6.5时加入N-甲基咪唑后，也观察到了间硝基苯硼酸类似的差示光谱变化。不仅在pH 6.5，而且在碱性pH条件下，间硝基苯硼酸与枯草杆菌蛋白酶BPN'结合时都会诱导出特征性的圆二色光谱。圆二色光谱滴定证实了间硝基苯硼酸-枯草杆菌蛋白酶复合物的化学计量比为1:1。间硝基苯硼酸被证明是一种用于丝氨酸蛋白酶催化位点的可逆发色探针。
