海参体壁中α-1,4淀粉酶的分离纯化及性质

Purifi cation and Characterization of α-1,4-Amylase in Body Wall of Sea Cucumber

通过采用匀浆、硫酸铵盐析、透析、DEAE-52阴离子交换层析、Sephacryl S-300凝胶层析等方法从海参体壁中分离纯化并得到了α-1,4淀粉酶。结果表明,该酶具有3条亚基链,分子质量约为420 k D;最适p H值为9.0,最适温度为80℃,90℃条件下保温30 min后仍有38%以上的相对酶活性,因此,该酶是一种具有较高热稳定性的碱性高温淀粉酶。K+、Fe3+和Mn2+对其有较强的抑制作用,Cu2+和Ca2+对其有较强的激活作用。

α-1,4-Amylase was extracted and isolated from the body wall of sea cucumber by homogenization,salting out with ammonium sulfate,dialysis,DEAE-52 anion exchange chromatography and Sephacryl S-300 gel chromatography sequentially.The results showed that the purified enzyme had three subunit chains according to the SDS-PAGE,with molecular weight of 420 k D;the optimum p H and temperature were 9.0 and 80 ℃;and the residual activity remained at least 38% after inactivation at 90 ℃ for 30 min.Therefore,this enzyme is a thermostable alkaline amylase.This amylase could be strongly activated by K+,Fe3+ or Mn2+ and inhibited by Cu2+ or Ca2+.