【摘要】 <正> 家蚕(Bombyx mori L.)与蓖麻蚕(Samia,ricini B)的丝蛋白氨基酸含量差异甚为显著;家蚕丝含量最多的为甘氨酸(42.8％),其次为丙氨酸(32.4％);而蓖麻蚕丝则以两氨酸含量为最高(50.5％),其次为甘氨酸(27.8％)(Kirimuru等,1962)。为了阐明丝蛋白主要氨基酸的形成机制,我们曾报道了这两种蚕丝腺中,自L-天门冬氨酸与α-酮戊二酸形成丙氨酸的机制(许延森等,1964a);体液乙醛酸及丙酮酸与丝蛋白相应氨基酸的含量之更多还原

【Abstract】 1. The free and protein amino acids in the hemolymphs of the fifth instar larvae of Samia ricini and Bombyx mori were determined quantitatively by paper chromato-graphy.2. The glutamic acid contents in the fat bodies and posterior divisions of silk-glands of the fifth instar larvae of Samia ricini and Bonibyx mori were found to he about 40% of the total free amino acids in these tissues.3. The enzymatic systems (L-asparatate-L-glutamate transaminase, L-alanine-L-glutamate transaminase, L-isoleucine, L-leucine, L-valine-L-glutamate transaminase, transamination between L-alanine, L-glutamate, L-aspartate and glyoxylate, ketoma-lonate) in the posterior divisions of silkglands of the fifth instar larvae of Samia ricini and Bombyx mori were compared. The relative activities of the transaminases of these two silkworms agree well with the relative amounts of glycine and alanine in their fibroins.4. The posterior divisions of the silkglands of Samia ricini and Bombyx mori were able to convert ketomalonic acid to glyoxylic acid and CO2. The conversion possibly included enzymatic as well as non-enzymatic deearboxylation of ketomalonate. The factor responsible for the latter process was heat and alcohol stable and dialyzable.5. The deearboxylation of ketomalonate in the posterior division of silkglands, fat bodies and Malpighian tubules of the fifth instar larvae of Samia ricini and Bombyx mori were compared.更多还原