黄粉虫幼虫小分子量抗茵肽的分离纯化

昆虫抗菌肽具有良好的抑菌效果，有望开发成新一代抗生素。本文以金黄色葡萄球菌和大肠杆菌混合液作为诱导源，采用针刺法使黄粉虫TenebriomolitorL．幼虫感染微生物产生抗菌肽，并对抗菌肽进行了提取、色谱分离纯化及抑菌活性检测。结果显示，诱导组和对照组的三氟乙酸粗提物无抑菌活性；经SephadexG50、SuperdexPeptide凝胶色谱分离后，从诱导组和对照组均可获得对革兰氏阳性菌金黄色葡萄球菌、枯草芽孢杆菌有抑菌作用的组分，而且诱导组活性明显高于对照组；通过Resource15RPC反相色谱分离纯化，从诱导组获得一具有明显抑制革兰氏阳性菌的组分，质谱检测该组分为混合肽，主要由分子量为1876．21u、1904．21u的小肽组成，可能是一种比Thanatin分子量更低的昆虫抗菌肽。

Isolation and purification of small antimicrobial peptide from larvae of mealworm, Tenebrio molitor

Antimicrobial peptides （AMPs） are so effective against bacteria that they are expected to become the new antibiotics. We induced mealworm, Tenebrio molitor L, , larvae to produce AMPs by pricking their abdomens with a stainless needle that had been dipped in a suspension of living Escherichia coli and Staphylococcus aureus. AMPs were then isolated and purified by methods including 0.1% trifluoroacetic acid （ v： v） extraction, gel filtration chromatography on Sephadex G - 50 and Superdex Peptide, and reverse phase high - performance liquid chromatography （ RP - HPLC）. Eventually, a fraction was obtained from the induced group with strong anti - S. aureus and anti - Bacillus subtilis activities. The analysis of matrix - assisted laser desorption ionization time - of - flight mass spectrometry （ MALDI - TOF MS） indicated that the fraction was composed of two small peptides with molecular masses of 1 876.21 u and 1 904.21 u respectively. This suggests that these peptides are insect AMPs of a lower molecular weight than Thanatin.