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. 2003 Sep;60(9):1944–1951. doi: 10.1007/s00018-003-3082-z

A small chimerically bifunctional monomeric protein: Tapes japonica lysozyme

K Takeshita 1, Y Hashimoto 1, T Ueda 1, T Imoto 1,2,
PMCID: PMC11138589  PMID: 14523554

Abstract

The lysozyme of the marine bilave Tapes japonica (13.8 kDa) is a novel protein. The protein has 46% homology with the destabilase from medicinal leech that has isopeptidase activity. Based on these data, we confirmed hydrolysis activity of T. japonica lysozyme against three substrates: L-γ-Glu-pNA, D-γ-Glu-pNA, and ε-(γ-Glu)-L-Lys. The optimal pH of chitinase and isopeptidase activity was 5.0 and 7.0, respectively. The isopeptidase activity was inhibited with serine protease inhibitor, but the lytic and chitinase activities were not. Moreover, only isopeptidase activity is decreased by lyophilization, but lytic and chitinase activities were not. We conclude that T. japonica lysozyme expresses isopeptidase and chitinase activity at different active sites.

Keywords: Lysozyme, Tapes japonica, chitinase, isopeptidase, invertebrate lysozyme, bifunctional

Footnotes

Received 25 February 2003; received after revision 29 May 2003; accepted 12 June 2003


Articles from Cellular and Molecular Life Sciences: CMLS are provided here courtesy of Springer

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