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Protein purification and nucleotide sequence of a lysozyme from the bacteria-induced larvae of the fall webworm, Hyphantria cunea

Author:
Park, H.Y., Park, S.S., Shin, S.W., Park, D.S., Kim, M.G., Oh, H.W., Joo, C.K.
Source:
Archives of insect biochemistry and physiology 1997 v.35 no.3 pp. 335-345
ISSN:
0739-4462
Subject:
lysozyme, messenger RNA, Hyphantria cunea, complementary DNA, structural genes, phylogeny, amino acid sequences, gene expression, nucleotide sequences, immune response, enzyme activity, Escherichia coli
Abstract:
A protein with lytic activity against Micrococcus luteus was purified from the hemolymph of the fall webworm, Hyphantria cunea, larvae challenged with live E. coli. A bacteriolytic protein of about 14,000 daltons in mass was purified by cation exchange chromatography and reverse-phased HPLC. The optimum pH and optimum temperature range for activity were around pH 6.2 and 50 degrees C, respectively, in a 100 mM phosphate buffer. The amino-terminal amino acid sequence of this protein was determined and the corresponding cDNA was isolated and analyzed. The deduced protein of 142 amino acid residues was composed of a putative leader sequence of 20 residues and the mature enzyme of 122 residues. The cloned lysozyme gene was strongly induced in response to bacterial injection, implying that the enzyme is a part of the immune response of H. cunea. Comparison with other known lysozyme sequences shows that our lysozyme belongs to the chicken lysozyme.
Agid:
1438850