Halophilic characterization of starch-binding domain from Kocuria varians α-amylase.
The tandem starch-binding domains (KvSBD) located at carboxy-terminal region of halophilic α-amylase from moderate halophile, Kocuria varians, were expressed in E. coli with amino-terminal hexa-His-tag and purified to homogeneity. The recombinant KvSBD showed binding activity to raw starch granules at low to high salt concentrations. The binding activity of KvSBD to starch was fully reversible after heat-treatment at 85°C. Circular dichroism and thermal scanning experiments indicated that KvSBD showed fully reversible refolding upon cooling after complete melting at 70°C in the presence of 0.2-2.0M NaCl. The refolding rate was enhanced with higher salt concentration.
Biochemistry and Applied Biosciences, The United Graduate School of Agricultural Sciences, Kagoshima University, Korimoto, Kagoshima, Japan.
Rui
R
Yamaguchi
Yasuhiro
Y
Inoue
Hiroko
H
Tokunaga
Matsujiro
M
Ishibashi
Tsutomu
T
Arakawa
Jun-ichi
J
Sumitani
Takashi
T
Kawaguchi
Masao
M
Tokunaga
D001407:Bacillus / Q000378:metabolism; D002942:Circular Dichroism; D006358:Hot Temperature; D007700:Kinetics; D008837:Micrococcus / Q000201:enzymology*; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D012492:Salts / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D012995:Solubility; D013213:Starch / Q000737:chemistry; D055672:Static Electricity; D013499:Surface Properties; D013696:Temperature; D000516:alpha-Amylases / Q000737:chemistry*
D011993:Recombinant Fusion Proteins; D012492:Salts; D012965:Sodium Chloride; D013213:Starch; D000516:alpha-Amylases