Fractionation of β-Lactamase from Bombyx mor・j

To date, I have researched lectin related proteins in the hemolymph of the domesticated silkworm, Bombyx mo パin relation to the activation of the 召.観θパhumora 囗ectin (Kato, 2006; Kato and Takeuchi, 2006). In the previous work (Kato, 2007), two spots obtained by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE)on lectin related proteins from the larval hemolymph of the 召.踟θパwere eχcised from the gels and subjected to in-gel tryptic digestion, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis, and a SWISS-PROT protein database search (Madi d α/.,2003; Zhang et al., 2005). The results identified one of spots obtained by 2D PAGE as β-lactamase (EC3.5.2.6). I was able to obtain these very interesting results taking into consideration the defense mechanism of 召. mori, because β-lactamase is known as a hydrolase which reduces anti-bacterial characteristics by cleaving to the β-lactam ring of the lactam medicine like penici IIIn (Lee, 1987; Sawai d αL, 1995). Accordingly, I confirmed the existence of β-lactamase in the hemolymph of召. 踟θパby an assay of β-lactamase activity, and guessed that β-lactamase should be necessary during the metamorphosis of 召mori (Kato, 2008). The aim of the present study was to fractionate β-lactamase in the hemolymph and fat body from 召.・ a・j by means of gel filtration or Mono Q ion chromatography. This investigation provided useful information for the understanding of the defense system of 召.