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A strain ofSerratia marcescensthat produced chondroitinase was isolated from soil. It produced a novel chondroitinase AC, which was purified to homogeneity. The enzyme was composed of two identical subunits of 35 kDa as revealed by SDS-PAGE and gel filtration. The isoelectric point for the chondroitinase AC was 7.19. Its optimal activity was at pH 7.5 and 40 °C. The purified enzyme was active on chondroitin sulfates A and C and hyaluronic acid, but was not with chondroitin sulfate B (dermatan sulfate), heparin or heparan sulfate. The apparentKm andVmax of the chondroitinase AC for chondroitin sulfate A were 0.4 mg ml-1 and 85 mmol min-1 mg-1, respectively, and for chondroitin sulfate C, 0.5 mg ml-1 and 103 mmol min-1 mg-1, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The cDNA (GenBank, AY251538) encoding bullfrog growth hormone (fGH) was cloned by RT-PCR from the total RNA of pituitary glands. Its sequence encoded a putative polypeptide of 215 amino acids, including a signal peptide of 25 amino acids with no change to those of other previous reported bullfrog GHs. The fGH precursor shares 98.1, 96.3, and 95.3% homologies to those of other bullfrog GHs (AAB24792, AAB19428, CAA31038) in amino-acid sequence and its nucleotide sequences of the coding region shares 99.1 and 98.5% homologies to those of previous bullfrog GH genes (S52027 and X12520). The fGH cDNA was also efficiently expressed in Escherichia coli carrying a plasmid pGfGH in which the cDNA was under the control of GST promoter of pGEX1-λT. The expressed fusion protein GST-fGH is comprised about 29.3% of the total cellular protein in such bacteria. The purified GST-fGH cannot only showed a obvious dose–response curve when it reacted with the hepatic membrane receptor proteins from bullfrog, but also significantly increased the body weight and length of bullfrog after twice injection and such effects lasted two or three weeks after the last injection with purified GST-fGH. [Copyright &y& Elsevier]