Stability of Natrialba magadii NDP kinase: comparisons with other halophilic proteins.
Nucleoside diphosphate kinase from the haloalkaliphilic archaeon Natrialba magadii (Nm NDPK) is a homooligomeric hexamer with a monomer molecular weight of 23 kDa. Its main function is to exchange gamma-phosphates between nucleoside triphosphates and diphosphates. Previously it was shown that Nm NDPK is active over a wide range of NaCl concentrations, which is not typical of extremely halophilic proteins. In this paper more detailed investigations of kinase function and stability were carried out using circular dichroism, differential scanning calorimetry, size-exclusion chromatography, and biochemical methods. A possible mechanism for stabilization of halophilic proteins that allows them to function in a wide range of NaCl concentrations is proposed.
Polosina
Yaroslava Y
YY
Institute of Protein Research, Russian Academy of Sciences, Pushchino. slava@vega.protres.ru
Zamyatkin
Dmitry F
DF
Kostyukova
Alla S
AS
Filimonov
Vladimir V
VV
Fedorov
Oleg V
OV
D000596:Amino Acids / Q000032:analysis; D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D004795:Enzyme Stability; D006216:Halobacteriaceae / Q000201:enzymology*; D008970:Molecular Weight; D009701:Nucleoside-Diphosphate Kinase / Q000737:chemistry* / Q000378:metabolism*; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012965:Sodium Chloride; D013050:Spectrometry, Fluorescence; D013696:Temperature
D000596:Amino Acids; D019843:Archaeal Proteins; D012965:Sodium Chloride; D009701:Nucleoside-Diphosphate Kinase