摘要
嗜热链霉菌(Thermostreptomyces sp.)T485的除去菌体的培养液,经硫酸铵盐析,Sepha-dex G-100、DEAE-Sephadex A-50及羟基磷灰石等柱层柝,得到了凝胶电泳均一的过氧化氢酶,纯化了954倍,得率为7%。用浓度梯度 PAGE 测定分子量为152000,SDS-PAGE 测定亚基分子量为57000,凝胶薄层等电点聚焦测定等电点为4.25。过氧化氢酶的反应最适温度为60℃,最适 pH 为7.0;对 H_2O_2的 K_m 为50mmol.L^(-1),V_(max)值为6.0 mmol·min^(-1)·mg^(-1)。NaN_3和 Hg^(2+)对酶活力有强烈抑制作用,Ca^(2+)对酶活力有激活作用。测定了波长200—500nm 的吸收光谱,在405nm 处有明显的吸收峰。根据受 NaN_3抑制和吸收光谱性质,推测它为含血红素酶。此外还测定了过氧化氢酶的氨基酸组成。
A catalase was purified to PAGE ho-mogenous from the culture supernatant of astrain of Thermostreptomyces sp.by am-monium sulfate precipitation and successivecolumn chromatography on Sephadex G-100,DEAE-Sephadex A-50 and hydroxyapatitewith 954-fold purification and 7% recovery.The Mr and subunit Mr estimated with con-centration gradient PAGE and SDS-PAGEwere 152000 and 57000 respectively.Theisoelectric point was 4.25 determined withPAG-IEF.The optimum pH of catalase was7.0,optimum temperature was 60℃,The K_m value and V_(max) for H_2O_2 were50mmol·L^(-1) and 6.0mmol·min^(-1)·mg^(-1)respectively.The enzyme was stronglyinhibited by NaN_3 and Hg^(2+),and activ-ated by Ca^(2+).The absorption spectra of catalase show-ed a sharp peck at 405 nm,similar to that ofthe heme containing catalase.The aminoacid composition of the catalase has beendetermined.
出处
《微生物学报》
CAS
CSCD
北大核心
1990年第5期336-343,共8页
Acta Microbiologica Sinica
基金
国家自然科学基金
关键词
嗜热链霉菌
过氧化氢酶
Catalase
Thermophilic actinomyces
Thermostreptomyces sp
