Isolation and sequence of a novel amphibian pancreatic chitinase.
An approximately 60-kDa protein with chitinase activity was purified from the pancreas of the toad Bufo japonicus. Its specific activity was 4.5 times higher than that of a commercial bacterial chitinase in fragmenting crab shell chitin, and its optimal pH was approximately 6.0. A cDNA clone encoding a protein consisting of 488 amino acid residues, including part of the peptide sequence determined from the isolated protein, was obtained from a toad pancreas cDNA library. The deduced amino acid sequence indicated that the protein contained regions with high homology to those present in chitinases from different species, with the amino acid residues for the chitinase activity and the chitin-binding ability being completely conserved. We designate the protein as toad pancreatic chitinase (tPCase). Northern blot analysis revealed the mRNA of this enzyme to be expressed exclusively in the pancreas. Toad PCase is the first amphibian chitinase to be identified as well as the first pancreatic chitinase identified in a vertebrate.
Oshima
Hiroyuki
H
Department of Biology, School of Education, Waseda University, Nishi-waseda 1-6-1, Shinjuku-ku, Tokyo 169-8050, Japan.
Miyazaki
Rieko
R
Ohe
Yoshihide
Y
Hayashi
Hiroaki
H
Kawamura
Kosuke
K
Kikuyama
Sakae
S
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002025:Bufonidae / Q000235:genetics; D002688:Chitinases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010179:Pancreas / Q000201:enzymology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
D018076:DNA, Complementary; D012333:RNA, Messenger; D002688:Chitinases