Nakamura Y, Sato T, Emi M, Miyanohara A, Nishide T, Matsubara K
Gene. 1986;50(1-3):239-45. doi: 10.1016/0378-1119(86)90328-8.
A cDNA fragment coding for human salivary alpha-amylase precursor was joined to the promoter of the Saccharomyces cerevisiae PHO5 gene, and the recombinant gene was inserted into a vector plasmid capable of autonomous replication in yeast. Yeast cells transformed with this recombinant plasmid synthesized about 5 X 10(5) molecules of the enzyme per cell when synthesis was induced by deprivation of inorganic phosphate and released about half of the synthesized enzyme into the medium. The enzyme is stable, and exhibited the same specific activity as alpha-amylase in human saliva. The amylase-producing yeast grew on starch and produced alcohol.
编码人唾液α-淀粉酶前体的cDNA片段与酿酒酵母PHO5基因的启动子连接，然后将重组基因插入能够在酵母中自主复制的载体质粒。当通过剥夺无机磷酸盐诱导合成时，用这种重组质粒转化的酵母细胞每个细胞合成约5×10⁵个酶分子，并将约一半合成的酶释放到培养基中。该酶很稳定，并且表现出与人类唾液中的α-淀粉酶相同的比活性。产生淀粉酶的酵母在淀粉上生长并产生酒精。
