Temperature, organic solvent and pH stabilization of the neutral protease from Salinovibrio proteolyticus: significance of the structural calcium.
In order to clarify the impact of Ca-binding sites (Ca1 and 2) on the conformational stability of neutral proteases (NPs), we have analyzed the thermal, pH and organic solvent stability of a NP variant, V189P/A195E/G203D/A268E (Q-mutant), from Salinovibrio proteolyticus. This mutant has shown to bind calcium more tightly than the wild-type (WT) at Ca1 and to possess Ca2. Q-mutant was resisted against autolysis, thermoinactivation and pH denaturation in a Ca-dependent manner and exhibited better activity in organic solvents compared to the WT enzyme. These results imply that Ca1 and Ca2 are important for the conformational stability of NPs.
Department of Biochemistry, Tarbiat Modares University, Tehran, Iran.
S Mohsen
SM
Asghari
Khosro
K
Khajeh
Arastoo Badoei
AB
Dalfard
Mohammad
M
Pazhang
Hamid Reza
HR
Karbalaei-Heidari
D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D012997:Solvents / Q000737:chemistry*; D013696:Temperature; D014737:Vibrionaceae / Q000201:enzymology*
D001426:Bacterial Proteins; D012997:Solvents; D010447:Peptide Hydrolases; D002118:Calcium