Open AccessKetohexokinase (ATP:D-fructose 1-phosphotransferase) from a halophilic archaebacterium, Haloarcula vallismortis: purification and properties
Author(s) -
Vidhya Rangaswamy,
Wijaya Altekar
Publication year - 1994
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.176.17.5505-5512.1994
Subject(s) - biology , biochemistry , phosphotransferase , fructose , enzyme , halophile , pep group translocation , molecular mass , microbiology and biotechnology , genetics , bacteria , phosphoenolpyruvate carboxykinase
Ketohexokinase (ATP:D-fructose 1-phosphotransferase [EC 2.7.1.3]), detected for the first time in a prokaryote, i.e., the extreme halophile Haloarcula vallismortis, was isolated and characterized from the same archaebacterium. This enzyme was characterized with respect to its molecular mass, amino acid composition, salt dependency, immunological cross-reactivity, and kinetic properties. Gel filtration and sucrose density gradient centrifugation revealed a native molecular mass of 100 kDa for halobacterial ketohexokinase, which is larger than its mammalian counterpart. The enzyme could be labeled by UV irradiation in the presence of [ gamma-32P]ATP, suggesting the involvement of a phosphoenzyme intermediate. Other catalytic features of the enzyme were similar to those of its mammalian counterparts. No antigenic cross-reactivity could be detected between the H. vallismortis ketohexokinase and the ketohexokinases from different rat tissues.