Diego-García E, Abdel-Mottaleb Y, Schwartz E F, de la Vega R C Rodríguez, Tytgat J, Possani L D
Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, Avenida Universidad 2001, Cuernavaca, 62210, Mexico.
Cell Mol Life Sci. 2008 Jan;65(1):187-200. doi: 10.1007/s00018-007-7370-x.
Among the scorpion venom components whose function are poorly known or even show contrasting pharmacological results are those called "orphan peptides". The most widely distributed are named beta-KTx or scorpine-like peptides. They contain three disulfide bridges with two recognizable domains: a freely moving N-terminal amino acid sequence and a tightly folded C-terminal region with a cysteine-stabilized alpha/beta (CS-alphabeta) motif. Four such peptides and three cloned genes are reported here. They were assayed for their cytolytic, antimicrobial and K (+) channel-blocking activities. Two main characteristics were found: the existence of an unusual structural and functional diversity, whereby the full-length peptide can lyse cells or kill microorganisms, and a C-terminal domain containing the CS-alphabeta motif that can block K (+) channels. Furthermore, sequence analyses and phylogenetic reconstructions are used to discuss the evolution of this type of peptide and to highlight the versatility of the CS-alphabeta structures.
在蝎毒成分中，功能鲜为人知甚至呈现出相互矛盾的药理结果的是那些被称为“孤儿肽”的成分。分布最广泛的被命名为β-KTx或类蝎毒素肽。它们含有三个二硫键，具有两个可识别的结构域：一个自由移动的N端氨基酸序列和一个紧密折叠的C端区域，带有一个半胱氨酸稳定的α/β（CS-αβ）基序。本文报道了四种这样的肽和三个克隆基因。对它们进行了溶细胞、抗菌和钾离子通道阻断活性的检测。发现了两个主要特征：存在不寻常的结构和功能多样性，即全长肽可以裂解细胞或杀死微生物，以及一个包含CS-αβ基序的C端结构域可以阻断钾离子通道。此外，还利用序列分析和系统发育重建来讨论这类肽的进化，并突出CS-αβ结构的多功能性。
