Part:BBa_K1104999

Chitinase-63 hydrolyzes radioactive chitin most rapidly at pH 6 and has approximately half-maximal rates for this reaction at pH 4.5 and 7.5. By contrast, the maximum rate of hydrolysis of the 4-methylumbelliferyl trisaccharide occurs at pH 4 in 0.1 M citrate buffer. The enzyme catalyzes hydrolysis of the trisaccharide derivative over a wide pH range with appreciable activity even in 0.1 M glycine buffer, pH 10.4 (approximately 10% of the rate at pH 4). Chitinase-63 has a high affinity for the oligosaccharide substrates; Km for the 4-MU trisaccharide is about 0.5 µM and for the 4-MU disaccharide is about 5 µM. Higher concentrations produce severe substrate inhibition. Chitinase-63 is stable when heated at 63 ℃, but is largely inactivated when heated at 80 ℃ for 1 min. Chitinase-63 produce 4-methylumbelliferone more rapidly from the trisaccharide than from the disaccharide derivative, and both enzymes form more 4-methylumbelliferone than 4-MU- GlcNAc from both the 4-MU trisaccharide and tetrasaccharide. Thus, chitinase-63 might be classified as endochitinases.

sequence: gaattcatcg atatctagat cccgggatct agttttccct gtcagtcaca ggttcaacca ctggccgcca cattggtcca gacctattga cctgtggtcc agacctttct attctcgcgc actgcgggca tgaggctcag tcatgccctc gacaacatcc ccataaaagg aggcgcacat gcgcttcaga cacaaagccg cggcactcgc agcgaccctg gcgcttcccc tcgccggcct ggtcggcctc gcgagcccgg cccaggcggc caccagcgcg acggccacct tccagaagac ctcggactgg ggcacgggct tcggcggcaa gtggacggtg aagaacaccg gcaccacctc cctcagctcc tggaccgtcg agtgggactt cccctccggc accaaggtca cctccgcctg ggacgccacc gtcaccaact ccgccgacca ctggaccgcc aagaacgtcg gctggaacgg gacgctcgcc cccggcgcct cggtctcctt cggcttcaac ggcagcggcc cgggctcccc gtccggctgc aagatcaacg gcggcagctg cgacggctcc tcggtccccg gtgacgaggc cccctccgcg cccggcacgc ccaccgcctc gaacatcacc gacacctcgg tgaaactgtc ctggtcggcg gccaccgacg acaagggcgt caagaactac gacgtcctgc gcgacggcgc gacggtcgcc accgtcaccg gcaccaccta cacggacaac ggccttacca agggcaccga ctactcctac agcgtcaagg cccgcgacac cggcgaccag accggtccgg ccagcggctc cgtgaaggtc acgaccaccg gcggagacgg cggcgagccg aacccgaacc cgggtgccga ggtcaagatg ggctacttca ccaactgggg cgtctacggg cgcaactacc acgtgaagaa cctggtcacc tccggctccg ccgagaagat cacgcacatc aacttacgct tcggcaacgt ccagggcggc aagtgcacca tcggcgacgc ctacgccgac tacgacaagg cgtacaccgc cgaccagtcc gtcgacggcg tcgcggacac ctgggaccag ccgctgcgcg caaacttcaa ccagctgcgc aacttgaagg ccgagtaccc gcacatcaag atcctctact ccttcggcgg ctggacctgg tccggcggct tccccgacgc cgtgaagaac ccggccgcgt tcgcgaagtc ctgccacgac ctggtcgagg acccgcgctg ggccgacgtc ttcgacggca tcgacctgga ctgggagtac cccaacgcct gcggtctcag ctgtgacgag accagcgccc ccaacgcctt cagcagcatg atgaaggcca tgcgcgccga gttcggccag gactacctga tcaccgcggc cgtcaccgcc gacggctcgg acggcggcaa gatcgacgcc gccgactacg gcgaggcctc gaagtacatc gactggtaca acgtgatgac gtacgacttc ttcggcgcct gggcgaagaa cggcccgacc gccccgcact cgccgctcaa cgcgtacgac ggcatcccgc agcagggctt caccaccgcc gacgcgatgg cgaagttcaa gtccaagggc gtcccggccg acaagctcct gatcggcatc ggcttctacg gccgcggctg gaccggcgtc acgcagtccg cgcccggcgg caccgccacc ggcccggcgg ccggcaccta cgaggccggc atcgaggact acaaggtcct caagaacagc tgcccggcca ccggcaccgt cgccggcacc gcgtacgccc actgcggcac caactggtgg tcctacgaca ccccggccac catcaagtcg aagatggact gggcggagca gcagggtctc ggcggcgcct tcttctggga gttcagcggc gacaccacga acggcgaact ggtgagcgcc atcgacagcg gcctgaagta gaccgcgtag aaaagctccc taagcgacgt tgacgcgctg accgggcggg gctgcttcca gccacgcgag aaatccggtc agcgcgtctt cgctcatcgc cagttcgagc cgtgtgcccc ggtgcagaca ggccaggacc acggcgtcgg agagcaaagc gagttcctcc tcgccgtccg gcacccggcg gccggccacc tcgatcgcgg agcgttcgag cacgcggcgc gggcgggggg agtacgagaa cacgcggtac catcga