枯草杆菌蛋白酶与3,4-二羟基-2-蒽醌磺酸钠的作用机理

The Reaction Mechanism Between Bacillus Subtilis Proteinase and Sodium 3,4-Dihydro-2-anthraquinone sulfonate

用UV光谱法研究了枯草杆菌蛋白酶 (BSP)在pH =4 2 0的酸性溶液中与 3,4 二羟基 2 蒽醌磺酸钠(ARS)的相互作用。测得生成的缔合物的最大吸收峰为 5 15nm ,与试剂相比红移 95nm。应用平衡透析法、摩尔比法和双波长法进行测定 ,结果表明 ,表观摩尔吸光系数εB1=5 89× 10 3 L/ (mol·cm) ,εB2 =4 6 8×10 3 L/ (mol·cm) ,结合数n1=13和n2 =4 5 ,积累平衡常数 β1=5 2 7× 10 4L/mol和 β2 =3 5 4× 10 5L/mol。第 1类结合数完全符合BSP空间构象中活性中心的作用原子数。研究发现 ,该反应基本符合Scatchard模型 ,BSP与ARS之间的作用以电荷力为主、疏水力为辅。

The interaction of bacillus subtilis proteinase(BSP) and sodium 3,4-dihydro-2-anthraquinone sulfonate(Alizarin Red S, ARS) was investigated by spectrophotometric method in acidic solution(pH=4.20). The red color of the solution indicates the formation of the new compound. The maximum absorption peak of the colored species was at 515 nm. It is shifted from 420 nm of ARS. Balance dialysis method, molar ratio method and double wavelengh method were adopted to investigate the association formation. The following results were obtained: binding number n_1=13, n_2=45; apparent molar absorptivity ε_B1=5.89× 10~3 L/(mol·cm), ε_B2=4.68×10~3 L/(mol·cm); accumulative equilibrium constant β_1=5.27× 10~4 L/mol, β_2=3.54×10~5 L/mol. It is found that combination of BSP with ARS conforms to Scatchard model and the first type binding number completely conform to functional atom number of BSP activity center in its space conformation. It is suggested that the combination between BSP and ARS is due to the electrostatic force(primary action force)and hydrophobic force.