Kiyatkin N, Dulubova I, Grishin E
Shemyakin Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow.
Eur J Biochem. 1993 Apr 1;213(1):121-7. doi: 10.1111/j.1432-1033.1993.tb17741.x.
alpha-Latroinsectotoxin (alpha-LIT), purified from venom glands of the black widow spider Latrodectus mactans tredecimguttatus, is a presynaptic neurotoxin selective only for insects. A cDNA encoding the putative alpha-LIT precursor was isolated from a spider venom gland cDNA library. The cDNA contains a 4236-base-pair open reading frame corresponding to a 157826-Da protein composed of 1411 amino acids. The mature alpha-LIT, with molecular mass approximately 130 kDa, is probably derived from double processing in the N-terminal and C-terminal regions of the primary translation product. The structure region, extending over residues 464-1176, is composed almost entirely of ankyrin-like repeats which represent a motif also found in the alpha-latrotoxin (alpha-LTX), which has selective action on vertebrates. Total alignment of the alpha-LIT and alpha-LTX amino acid sequences reveals an overall similarity of 34.1%. Strong sequence divergence is observed in analogous cysteine-rich regions situated within the ankyrin-repeat domains of both alpha-LIT and alpha-LTX.
从红斑寇蛛（Latrodectus mactans tredecimguttatus）毒腺中纯化得到的α- Latroinsectotoxin（α-LIT）是一种仅对昆虫有选择性的突触前神经毒素。从蜘蛛毒腺cDNA文库中分离出了编码假定α-LIT前体的cDNA。该cDNA包含一个4236个碱基对的开放阅读框，对应于一个由1411个氨基酸组成的157826道尔顿的蛋白质。成熟的α-LIT分子量约为130 kDa，可能源自初级翻译产物N端和C端区域的双重加工。延伸至第464 - 1176位残基的结构区域几乎完全由锚蛋白样重复序列组成，这种基序也存在于对脊椎动物有选择性作用的α- latrotoxin（α-LTX）中。α-LIT和α-LTX氨基酸序列的全面比对显示总体相似性为34.1%。在α-LIT和α-LTX的锚蛋白重复结构域内类似的富含半胱氨酸区域观察到强烈的序列差异。
