摘要
采用NBS、PMSF、IAc、BrAc、SUAN、TNBS、PCMB、DTT以及金属离子和相关试剂在一定条件下选择性修饰蔗糖酶.结果表明:0.5 mmol/L的PMSF使酶活性丧失95%,10μmol/L的NBS使酶活性丧失93%,0.5 mmol/L的PCMB使酶活性降至12%,酶修饰呈一级反应,推测Trp、Ser的残基可能是薄荷叶片蔗糖酶的活性必需基团,而His、Lys的残基不在薄荷蔗糖酶的活性中心.
The invertase chemical reagents, i.e. from the fresh leaves of Mentha haplocaly PMSF, NBS, IAc, BrAc, SUAN, TNBS, Briq. was selectively modified by eight PCMB or DTT, together with metal ions and other reagents. The enzyme activity was found to decrease significantly after modification by PMSF, NBS and PCMB. Studies of the chemical modification demonstrated that Tryptophan, Serine and Cysteinyl residues are essential functional groups inside of the invertase active site and suggested that Histidine and Lysine residues are not located in the enzyme active site, thus having no direct effect on enzyme activity.
出处
《西南大学学报（自然科学版）》
CAS
CSCD
北大核心
2007年第10期114-118,共5页
Journal of Southwest University(Natural Science Edition)
基金
重庆市科委资助项目CSTC(2004AC1012)
关键词
薄荷
蔗糖酶
化学修饰
Mentha haplocaly Briq.
invertase
chemical modification
