Abstract：
Numerous articles have reported the involvement of linker in regulating bioactivity of tandem-repeat galectins. We hypothesize that linker interacts with N/C-CRDs to regulate the bioactivity of tandem-repeat galectins. To further investigate structural molecular mechanism of linker in regulating bioactivity of Gal-8, Gal-8LC was crystallized. Gal-8LC structure revealed formation of β-strand S1 by Asn174 to Pro176 from linker. S1-strand interacts with C-terminal of C-CRD via hydrogen bond interactions, mutually influencing their spatial structures. Our Gal-8 NL structure have demonstrated that linker region from Ser154 to Gln158 interacts with the N-terminal of Gal-8. Ser154 to Gln158 and Asn174 to Pro176 are likely involved in regulation of Gal-8\'s biological activity. Our preliminary experiment results revealed different hemagglutination and pro-apoptotic activities between full-length and truncated forms of Gal-8, indicating involvement of linker in regulating these activities. We generated several mutant and truncated forms of Gal-8 (Gal-8 M3, Gal-8 M5, Gal-8TL1, Gal-8TL2, Gal-8LC-M3 and Gal-8_177-317). Ser154 to Gln158 and Asn174 to Pro176 were found to be involved in regulating hemagglutination and pro-apoptotic activities of Gal-8. Ser154 to Gln158 and Asn174 to Pro176 are critical functional regulatory regions within linker. Our study holds significant importance in providing a profound understanding of how linker regulates biological activity of Gal-8.
摘要：
许多文章报道了接头参与调节串联重复半乳糖凝集素的生物活性。我们假设接头与N/C-CRD相互作用以调节串联重复半乳糖凝集素的生物活性。为了进一步研究接头调节Gal-8生物活性的结构分子机制,结晶Gal-8LC。Gal-8LC结构揭示了由接头的Asn174至Pro176形成β链S1。S1链通过氢键相互作用与C-CRD的C端相互作用，它们的空间结构相互影响。我们的Gal-8NL结构已经证明从Ser154到Gln158的接头区与Gal-8的N末端相互作用。Ser154至Gln158和Asn174至Pro176可能参与Gal-8生物活性的调节。我们的初步实验结果表明，全长和截短形式的Gal-8具有不同的血凝和促凋亡活性，表明接头参与调节这些活性。我们产生了几种突变和截短形式的Gal-8(Gal-8M3、Gal-8M5、Gal-8TL1、Gal-8TL2、Gal-8LC-M3和Gal-8_177-317)。发现Ser154至Gln158和Asn174至Pro176参与调节Gal-8的血凝和促凋亡活性。Ser154至Gln158和Asn174至Pro176是接头内的关键功能调节区。我们的研究对于深入了解接头如何调节Gal-8的生物活性具有重要意义。
