• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.147-153
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• 1999

Chitinolytic enzymes such as ${\beta}$-N-acetylglucosaminidase are major hydrolases involved in insect molting. We have isolated, sequenced a CDNA encoding ${\beta}$-N-acetylglucosaminidase from the silkworm, Bombyx mandarina, and compared its sequence with genes encoding chitinolytic enyzmes from other sources. The insert DNA in the clone is 3,284 nucleotides long with an open reading frame of 1,788 nucleotides that encodes a protein of 596 amino acids with a molecular weight of 68.2 kDa. There is a 3’-untranslated region composed with 1.479 nucleotides and are several potential polyadenylation signals. The predicted amino acid sequence apparently contains a leader peptide of 23 amino acids. A search of the amino acids sequence databases for sequences similarities to other ${\beta}$-N-acetylglucosaminidases or ${\beta}$-N-acetylhexosaminidases. The highest similarity matched with the enzyme from B. mori, which has a sequence identity of 95%. On the other hand, the identity between the B. mandarina enzyme and those from M. sexta and human are 70% and 24%, respectively.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2000.10a
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• pp.60-60
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• 2000

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• Journal of Life Science
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• v.9 no.4
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• pp.341-347
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• 1999

Insects use chitinolytic enzyme to digest chitin in the exoskelton during the molting process. We have isolated and sequenced a chitinase-encoding cDNA from the silkworm, Bombyx mandarina, compared its sequenced with genes encoding chitinolytic enzymes from other sources. The insert DNA in the clone is 2,675 nucleotides long with an open reading frame of 1,695 uncletides that encodes a protein of 565 amino acids with a molecuar weight of 63.4 kDa. The 3' -untranslated region of 889 nucleotides is AT-rich and contains two putative polyadenylation signals. The N-terminal sequence of the encoded protein contains numerous hydrophobic residues characteristic of a leader peptide. The amino acid alignment revealed that the endo-$\beta$-N-acetylglucosaminidase had 83% and 97% homology with M. sexta and B. mori, respectively. The deduced amino acid had two highly conserved region at the amino acid residues 97-111 and 139-148 that were related to the existing chitinase.