| 摘要 |
PURPOSE:To provide a glutamine synthesis enzyme having good heat resistance and further good trypsin and chymotrypsin resistances by purifying the crude extract of special cultured cells in three processes comprising an ammonium sulfate fractionation, a gel filtration and an affinity chromatography. CONSTITUTION:The crude extract of the cultured cells of Mycobacterium phlei is purified in three steps comprising a ammonium sulfate fractionation, a gel filtration and an affinity chromatography, thereby providing a glutamine synthesis enzyme having an enzymatic activity lowering of <=20% when heated at 65 deg.C for 60min and an enzymatic activity lowering of <=5% when treated with 1% trypsin or chymotrypsin for 2hr. The enzyme is preferably subjected to an adenosine-removing treatment using Micrococcal nuclease to form an enzyme for synthesizing phosphated glutamine. |
