Proteome analysis of silkworm (Bombyx mori L.) fat bodies was performed on the fifth-instar day-3 larva stage and the expression of proteins separated on two-dimensional polyacrylamide gels was tracked from the fourth-instar day-1 larva stage to the stage before adult moth. Proteins on the 2D-gels were excised manually and treated with 4-vinylpyridine for alkylation. Each spot was analyzed by capillary high-performance liquid chromatography coupled with ion-trap mass spectrometry after proteolysis using trypsin. In the previous report¹⁾, the amino acid sequence database obtained from the Drosophila genome was used for the protein identification. This analysis used the amino acid sequence data elucidated from the silkworm genome. Additionally, protein expression in fat bodies was compared with that at other stages and in other tissues described in the silkworm proteome database (http://kaiko2ddb.dna.affrc.go.jp/cgi-bin/search_2DDB.cgi). Several unidentified proteins from the previous report¹⁾ were identified with high Mascot scores. Induction and reduction of proteins during metamorphosis were observed as changes in spot concentration on sequential 2D-gels on the web.

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Proteomic analysis of silkworm hemolymph at the fifth-instar day-3 larva stage was performed by combination of two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. Prominent spots on 2D-gel were analyzed after trypsinization and proteins were identified by Mascot and Sequest using the amino acid sequence data obtained from the genome sequence of silkworm. The gel images were tracked from the fourth-instar day-1 larva stage to the stage before adult moth for twenty-one days. The results of mass spectrometry analysis and changes in gel images are summarized in the silkworm proteome database (http://kaiko2ddb.dna.affrc.go.jp/cgi-bin/search_2DDB.cgi).

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Proteins in the Malpighian tubes of silkworms were proteomically analyzed by combination of two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. Several proteins were identified using peptide mass fingerprinting by mass spectrometry and subsequent MS/MS analysis. In this analysis, the electrophoresis patterns of the Malpighian tubes were compared from the fourth-instar day-1 larva stage to the stage before adult moth. The results of mass spectrometry analysis and changes in gel images are summarized in the silkworm proteome database (http://kaiko2ddb.dna.affrc.go.jp/cgi-bin/search_2DDB.cgi).

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