聚脯氨酸-精氨酸与DNA相互作用的研究  

Study of poly proline-arginine interaction with DNA

作　　者：孙慧芳 卢静钘 何雪童 王艳伟[1] 杨光参[1] SUN Huifang;LU Jingxing;HE Xuetong;WANG Yanwei;YANG Guangcan(School of Mathematics and Physics,Wenzhou University,Wenzhou 325035,China)

机构地区：[1]温州大学数理学院,浙江温州325035

出　　处：《齐鲁工业大学学报》2025年第2期45-52,共8页Journal of Qilu University of Technology

基　　金：国家自然科学基金(12074289、11574232);浙江省自然科学基金面上项目(Y23A040004);浙江省高等教育“十四五”教学改革项目(jg20220509);浙江省研究生教育学会科研项目(2023-016)。

摘　　要：阳离子多肽与脱氧核糖核酸(DNA)的相互作用对生物学的基础研究以及在众多疾病的发病机理有着重要的意义。文章使用光学显微镜首先研究了聚脯氨酸-精氨酸(Poly PR)与单链鲑鱼精DNA相互作用的液液相分离(LLPS),发现多肽链长以及浓度的增加会促进LLPS;然后观察KCl浓度对Poly PR-DNA溶液LLPS的影响,发现KCl浓度的增大对其LLPS起到一个抑制的作用,当KCl的浓度大于800 mmol/L时,液滴消失;同时盐浓度不变时,随着DNA浓度的增大会对混合物的LLPS有促进作用。其次研究KCl浓度为100 mmol/L时Poly PR与双链鱼精DNA的相互作用的LLPS,发现双链DNA较单链DNA更难发生LLPS。最后,为了定量研究DNA与Poly PR的作用机制,用单分子磁镊(MT)测量Poly PR与DNA的临界凝聚力变化情况,从单分子层面分析其作用机理,实验结果表明随着Poly PR链长以及浓度的增大使得DNA的凝聚力也增大;并且测量了加入KCl溶液之后凝聚力的大小,发现凝聚力随着盐浓度的增加而减小。可见,单分子实验凝聚力结果与显微镜观察LLPS结果一致,得出多肽链的长度及浓度可以增强Poly PR与DNA的相互作用、盐离子浓度会减弱Poly PR与DNA的相互作用。The interaction between cationic peptides and deoxyribonucleic acid(DNA)is of great significance to the basic research of biology and the pathogenesis of many diseases.The article employs optical microscopy to initially investigate the liquid-liquid phase separation(LLPS)of poly proline-arginine(Poly PR)in the presence of single-stranded salmon sperm DNA.It was found that an increase in peptide chain length and concentration promotes LLPS.Then,the effect of KCl concentration onthe LLPS of Poly PR-DNAsolution was observed,and it was found that the increase of KCl concentration inhibits LLPS.When the KCl concentration exceeds 800 mmol/L,the droplets disappear;at the same time,when the concentration of salt is constant,the increase of DNA concentration will promote the LLPS of the mixture.Secondly,the effect of KCl concentration of 100 mmol/L at the interaction between PolyPR and double-stranded salmon DNA in liquid phase separation(LLPS)was studied,and it was found that the longer double-stranded salmon DNA are more difficult to undergo LLPS compared with single-stranded salmon DNA.Finally,in order to quantitatively study the mechanism of DNA and Poly PR interaction,a single-molecule force microscopy(MT)was used to measure the change of criticality of Poly PR and DNA,and analyze its mechanism from the single-molecule level.The experimental results showed that the increase of Poly PR chain length and concentration also led to an increase in DNA cohesion;and the size of cohesion was measured after the addition of KCl solution,which showed that the cohesion decreased with the increase of salt concentration.The experimental results obtained by single molecule show good consistency with the findings obtained by optical microscopy,which led to the conclusion that longer polypeptide chains and higher concentrations can enhance the interaction between Poly PR and DNA and decrease the interaction between Poly PR and DNA due to salt ions.

关 键 词：阳离子多肽 聚脯氨酸-精氨酸 凝聚力 LLPS 

分 类 号：TQ352.79[化学工程] TQ413