Kim Young-Ok, Kim Han-Woo, Park In-Suk, Lee Jeong-Ho, Lee Sang-Jun, Kim Kyung-Kil
Biotechnology Research Division, National Fisheries Research and Development Institute, 408-1, Gijang, Busan 619-902, South Korea.
J Gen Appl Microbiol. 2009 Oct;55(5):345-50. doi: 10.2323/jgam.55.345.
Citrobacter braakii produced an intracellular acid glucose phosphatase (AgpC) which was purified 986 fold to homogeneity with the specific activity of 286 units/mg. AgpC hydrolyzed a wide variety of phosphorylated compounds with high activity for glucose-1-phosphate and glucose-6-phosphate. The optimum pH and temperature for the enzyme activity was pH 5.0 and 45 degrees C, respectively. The Km value for glucose-1-phosphate was 5.12 mM with a Vmax 27.8 U mg(-1). Its molecular weight was 46 kDa by SDS-PAGE gel and the sequence of N-terminal amino acid residues identified was Gln-Thr-Ala-Pro-Glu-Gly-Tyr-Gln-Leu-Gln. The glucose-1-phosphatase gene (agpC) was cloned from the C. braakii genomic library. This gene comprised 1,242 nucleotides and encoded a polypeptide of 413 amino acids. The result of its BLAST search showed a significant similarity with glucose-1-phosphatase from enterobacteria such as E. coli, Enterobacter, Shigella, and Salmonella.
