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Isolation and characterization of the thermoresistant gluconokinase from Escherichia coli
Author(s) -
Vivas Eugenio I.,
Liendo Andreina,
Dawidowicz Karl,
Istúriz Tomás
Publication year - 1994
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.3620340207
Subject(s) - escherichia coli , isolation (microbiology) , microbiology and biotechnology , characterization (materials science) , biology , chemistry , materials science , biochemistry , nanotechnology , gene
It is known that two gluconokinases are inducibly expressed during the utilization of gluconate by E. coli . One is thermoresistant (activity stable for 3 h at 30 °C) and the other thermosensitive (losses 75% or more of its activity under the above conditions). The thermoresistant gluconokinase (EC 2.7.1.12) was isolated, purified and characterized for the first time from the E. coli mutant Ca26, a K12 derivative which lacks the thermosensitive activity. The enzyme was purified 43 fold with a recovery of 11%. The M r of the enzyme was 100 kDa with three equal subunits of approximately 29.5 kDa. The enzyme exhibited Michaelis‐Menten kinetics and the K m values for gluconate and ATP were 0.02 mM and 0.045 mM respectively.