Algaier J, Uyeda K
Research Service, Veterans Administration Medical Center, Dallas, TX.
Biochem Biophys Res Commun. 1988 May 31;153(1):328-33. doi: 10.1016/s0006-291x(88)81226-9.
A cDNA coding for 378 amino acids from the C-terminus of the human liver bifunctional enzyme, Fructose-6-phosphate,2-kinase:Fructose-2,6-bisphosphatase was isolated, sequenced, and expressed in E. coli K38. The expressed protein, identified by specific immunoassay, showed Fru 2,6-bisphosphatase activity but no Fru 6-P,2-kinase activity, demonstrating directly that the Fru 2,6-bisphosphatase activity resides in the C-terminal region. The Km for Fru 2,6-P2 was 4.3 microM. Fru 6-P was a noncompetitive inhibitor (Ki = 2.9 microM), and formed a phosphorylated intermediate when incubated with Fru 2,6[2-32P]P2. The subunit Mr of the enzyme was 36,600, and the active enzyme showed Mr = 37,000 by gel filtration.
从人肝脏双功能酶果糖-6-磷酸,2-激酶：果糖-2,6-二磷酸酶C末端编码378个氨基酸的cDNA被分离、测序，并在大肠杆菌K38中表达。通过特异性免疫测定鉴定的表达蛋白显示出果糖-2,6-二磷酸酶活性，但没有果糖-6-磷酸,2-激酶活性，直接证明果糖-2,6-二磷酸酶活性存在于C末端区域。果糖-2,6-二磷酸的Km为4.3微摩尔。果糖-6-磷酸是一种非竞争性抑制剂（Ki = 2.9微摩尔），并且在与果糖-2,6-[2-32P]二磷酸一起孵育时形成磷酸化中间体。该酶的亚基Mr为36,600，通过凝胶过滤，活性酶显示Mr = 37,000。
