By heterologous expression of a gene from Palaeococcus ferrophilus,a novel recombinant enzyme designated AMPf was obtained and proved to be an amylolytic enzyme with unique catalytic characteristics.The optimal temper...By heterologous expression of a gene from Palaeococcus ferrophilus,a novel recombinant enzyme designated AMPf was obtained and proved to be an amylolytic enzyme with unique catalytic characteristics.The optimal temperature and pH of AMPf were 50℃ and 7.0 respectively.Although sequence analysis and acarbose hydrolysis ability indicated that AMPf belongs to the subfamily GH13_20,interestingly,this enzyme hardly acts on cyclodextrins and pullulan distinguishing it from most enzymes in this subfamily.AMPf hydrolyzes starches to glucose,maltose,maltotriose,and maltotetrose as main products.AMPf mainly liberates glucose from starch with the concentration of 1%(w/v),while it shows malto-oligosaccharide forming ability with higher starch concentration of 4%(w/v).Also,the 4,6-ethylidene-4-nitrophenyl-maltoheptaose hydrolysis ability further indicates the unique combination endo-acting and glucose releasing exo-acting activtity of AMPf.AMPf could utilize maltose and maltotriose to produce malto-oligosaccharides by transglycosylation activity.It was proven AMPf has application protential in malto-oligosaccharides production.展开更多
基金financially supported by National Natural Science Foundation of China(32072268)The Science&Technology Pillar Program of Jiangsu Province(BE2018304)+3 种基金National First class Discipline Program of Food Science and Technology(JUFSTR20180203)National Natural Science Foundation of China(32072164)National Key Research and Development Program of China(2020YFC1606804)National Natural Science Foundation of China(32101990).
文摘By heterologous expression of a gene from Palaeococcus ferrophilus,a novel recombinant enzyme designated AMPf was obtained and proved to be an amylolytic enzyme with unique catalytic characteristics.The optimal temperature and pH of AMPf were 50℃ and 7.0 respectively.Although sequence analysis and acarbose hydrolysis ability indicated that AMPf belongs to the subfamily GH13_20,interestingly,this enzyme hardly acts on cyclodextrins and pullulan distinguishing it from most enzymes in this subfamily.AMPf hydrolyzes starches to glucose,maltose,maltotriose,and maltotetrose as main products.AMPf mainly liberates glucose from starch with the concentration of 1%(w/v),while it shows malto-oligosaccharide forming ability with higher starch concentration of 4%(w/v).Also,the 4,6-ethylidene-4-nitrophenyl-maltoheptaose hydrolysis ability further indicates the unique combination endo-acting and glucose releasing exo-acting activtity of AMPf.AMPf could utilize maltose and maltotriose to produce malto-oligosaccharides by transglycosylation activity.It was proven AMPf has application protential in malto-oligosaccharides production.
