title: [Isolation, purification and various properties of aspartate kinase from the cyanobacterium Plectonema boryanum].
abstract: The enzymic activity of aspartate kinase from filamentous cyanobacteria Plectonema boryanum at the logarithmic phase of growth has been studied. Aspartate kinase was purified eleven times and extracted in functionally homogeneous state from the cell-free extract by the methods of ammonium sulphate salting-out, ion-exchange chromatography and isoelectric focusing. Some physical and chemical characteristics of the enzyme have been studied: pI-7.2; optimum pH-9.0; optimum temperature-55 degrees C. The dependence of enzymatic reaction on concentration of substrates, co-enzymes, cofactors and protein has been established. Regulation of aspartate kinase activity by amino acids of the aspartate family has been investigated. L-threonine, L-homoserine and L-isoleucine (0.01-0.001 M) have a pronounced inhibitory effect. L-lysine and L-methionine are not immediate inhibitors of aspartate kinase but intensify the inhibitory effect of threonine by the cumulative mechanism.
authors.forename: T G
authors.initials: TG
authors.lastname: Lysenko
authors.forename: M I
authors.initials: MI
authors.lastname: Mendzhul
authors.forename: N V
authors.initials: NV
authors.lastname: Koltukova
authors.forename: O A
authors.initials: OA
authors.lastname: Shainskaia
authors.forename: S I
authors.initials: SI
authors.lastname: Perepelitsa
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001222:Aspartate Kinase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D002384:Catalysis; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D000458:Cyanobacteria / Q000201:enzymology* / Q000254:growth & development
chemical_list: D000596:Amino Acids; D001222:Aspartate Kinase
vernacular_title: Vydelenie, ochistka i nekotorye svoĭstva aspartatkinazy tsianobakterii Plectonema boryanum.