柞蚕抗菌肽D中精氨酸、赖氨酸和色氨酸等氨基酸残基的化学修饰
Studies on the modification of arginine, lysine and tryptophan residues in cecropin D from the Chinese oak silk moth, Antheraea pernyI
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摘要: 用不同的化学试剂修饰了柞蚕抗菌肽D中精氨酸、赖氨酸和色氨酸等氨基酸残基。NBS修饰抗菌肽D，以及氨肽酶M对抗菌肽D作用的结果表明色氨酸残基对抗菌肽D抑制E.coli D31的作用影响不大. CHD和MLH对精氨酸和赖氨酸残基的修饰,导致抗菌肽D失去抑制E.coli 的作用,但可逆地消除CHD和MLH的修饰作用后, 抗菌肽D 恢复了对E.coli D31的抑菌作用.这些结果初步认为, 抗菌肽D 抑菌作用与分子中的荷电性有关. 改变了分子的电荷, 也就同时失去了其抑菌功能.此外, 对精氨酸残基修饰的结果还表明, 抗菌肽D的免疫原性与精氨酸残基有关. 但是, 抗菌肽D 的面议决定簇与其生物活性中心并不完全平行.Abstract: The tryptophan, arginine and lysine residues of cecropin D were modified by N-bromosuccinimide (NBS), 1, 2-CYCLOHEXANEDIONE (CHD) and maleic little relationship to the antibacterial activity of the peptide against Escherichiacoli D31, but that the arginine and lysine residues were important to the cecropin D resulted in a total loss of its antibacterial activity against E. coli D31. When the arginine and lysine residues were each regenerated from the modified structures the antibacterial acivity of cecropin D was recovered. These results suggest that the antibacterial activity of cecropin D is related to the charge in the molecule. Ouchterlony double immunodiffusion showed that the antigenic determinant of cecropin D is closely connected with the arginine residues in the peptide.
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