US EPA

1432966 

Journal Article 

PhoN-type acid phosphatases of a heavy metal-accumulating Citrobacter sp.: Resistance to heavy metals and affinity towards phosphomonoester substrates 

Jeong, BC; Macaskie, LE 

1995 

Yes 

FEMS Microbiology Letters
ISSN: 0378-1097
EISSN: 1574-6968 

BIOSIS/95/32604 

130 

2-3 

2-3 

eng 

WOS:A1995RN91500016 

BIOSIS COPYRIGHT: BIOL ABS. An atypical Citrobacter sp. isolated from a heavy metal-polluted site has a PhoN-type acid phosphatase that is responsible for the precipitation of heavy metals as cell-bound metal phosphates via liberated inorganic phosphate, supplied via enzymic cleavage of a phosphomonoester substrate. Phosphatase activity, comprising two isoenzymes designated CPI and CPII, was resistant to cadmium (II), zinc (II) and lead (II), but sensitive to uranyl and vanadyl oxycations and cupric ion. The monovalent cations of mercury (I) and silver (I), and trivalent yttrium (III) were inhibitory, particularly to CPII. The anionic counterion did not influence metal toxicity. The Km of CPII towards some phosphomonoester substrates was higher than that of CPI, suggesting that although the two isoenzymes were shown previously to be closely related, subtle differences exist between them that justify their classification as separate isoenzymes, for which the physiological function is still obscure. 

Comparative Biochemistry; Biochemical Methods-General; Biochemical Studies-General; Biochemical Studies-Proteins; Biochemical Studies-Minerals; Biophysics-General Biophysical Techniques; Biophysics-Molecular Properties and Macromolecules; Enzymes-General and Comparative Studies; Enzymes-Methods; Enzymes-Chemical and Physical; Enzymes-Physiological Studies; Metabolism-General Metabolism; Metabolism-Energy and Respiratory Metabolism; Metabolism-Minerals; Metabolism-Proteins; Toxicology-General; Toxicology-Environmental and Industrial Toxicology; Morphology and Cytology of Bacteria; Physiology and Biochemistry of Bacteria; Genetics of Bacteria and Viruses; Microbiological Apparatus; Public Health: Environmental Health-Sewage Disposal and Sanitary Measures; Public Health: Environmental Health-Air; Food and Industrial Microbiology-Biodegradation and Biodeterioration; Enterobacteriaceae (1992- )