【摘要】 膜结合的γ-谷氨酰转肽酶(γ-GTP),广泛地分布于家蚕的中肠、马氏管、脂防体、体壁、后丝腺和脑组织中,马氏管和中肠的酶活力较高.产丝量较高的品种苏6×苏5,中肠γ-GTP活力也较高,各品种中肠γ-GTP活力峰均在5龄中期.大部分必需氨基酸是该酶很好的氨基酸受体,但谷氨酰胺等几种氨基酸明显抑制该酶活力.蚕中肠组织的GSH含量变化与γ-GTP活力变化有关.γ-GTP活力较高的苏6×苏5品种,其中肠GSH浓度也较高.以上结果反映出,家蚕中肠γ-GTP和GSH在吸收氨基酸,尤其是必需氨基酸中起重要作用.更多还原

【Abstract】 The membrane-bound γ-glutamyltr anspeptidase (γ-GTP ) was found occurring in midgut, Malpighian tubules, fat body, body wall, posterior silkgland and brain of silkworm, Bombyx mori. The γ-GTP activities of Malpighian tubules and midgut are higher than that of others. The γ-GTP activity of the midgut from the higher silk-product variety Su6 × Su5 is higher than that of Dong34 × Sul2.The γ-GTP activities are stimulated by over ten kinds of amino acids respectively. The most of the essential amino acids for insect growth and development are good receptors for γ-GTP. Howeuer L-glutamine which is excellent receptor for mammalian γ-GTP, inhibited strongly the γ-GTP from the silkworm.GSH contents of the silkworm midgut are higher at the 4th moulting and then decreased rapidly in the first three days of the 5th instar and increased again with days of 5th stardium. GSH titre of midgut from Su6×Su5 is higher that of Dong34 × Sul2.更多还原