为确定凝胶电泳后条带中DNA的长度和浓度,该文提出了一种通过DNA荧光强度精确分析DNA长度及浓度的有效方法。对D2000 DNA ladder进行凝胶电泳,采集图像并进行处理。利用荧光强度与DNA浓度之间的线性关系以及迁移距离与DNA长度的线性关...为确定凝胶电泳后条带中DNA的长度和浓度,该文提出了一种通过DNA荧光强度精确分析DNA长度及浓度的有效方法。对D2000 DNA ladder进行凝胶电泳,采集图像并进行处理。利用荧光强度与DNA浓度之间的线性关系以及迁移距离与DNA长度的线性关系进行数据分析。结果显示:采用SYBR Green I作为荧光染料电泳DNA时,图像中各像素点中的绿色与红色灰度值可以反映DNA的特征信息,且绿色灰度值明显高于红色灰度值;对于小于2000 bp的DNA片段,其分子量与迁移距离呈反比例函数关系,当二者分别取对数时,其相关系数达0.971,可用于建立DNA分子量与迁移距离的数学模型以计算DNA分子量;通过计算电泳峰峰值及电泳峰积分面积,发现对于浓度比为2∶1的两个DNA条带,二者的比值为2.16与1.96、2.11与1.94、2.16与1.93,表明电泳峰积分面积能更有效地反映DNA的真实浓度值。该研究对于核酸凝胶电泳仪的开发具有重要应用价值。展开更多
肽基水凝胶作为生物活性材料在药学、纳米材料化学、组织工程等领域受到广泛关注。肽水凝胶的设计往往遵循自下而上的思路,即基于分子自组装的方法,以微观结构为基础扩展到宏观结构的形成。这种从微观角度出发的方法缺乏具体的模型阐述...肽基水凝胶作为生物活性材料在药学、纳米材料化学、组织工程等领域受到广泛关注。肽水凝胶的设计往往遵循自下而上的思路,即基于分子自组装的方法,以微观结构为基础扩展到宏观结构的形成。这种从微观角度出发的方法缺乏具体的模型阐述,初学者往往难以上手。因此,我们根据以β-折叠为基本自组装结构的肽基水凝胶的研究,总结了氨基酸对于肽自组装行为以及凝胶结构与应用的影响,期望可以帮助研究者在设计多肽序列时可以尽快地找到切入点,开发出具有特殊功能的肽基水凝胶材料。As bioactive materials, peptide-based hydrogels have attracted extensive attention in the fields of pharmacy, nanomaterial chemistry, tissue engineering, etc. The design of hydrogels often follows the bottom-up approach, that is the method based on molecular self-assembly, extending from microstructure to the formation of macrostructure. But this method from the micro-perspective lacks specific model elaboration, making it difficult to get started for beginners. Therefore, based on some studies on peptide-based hydrogels with β-sheet as the basic self-assembly structure, we summarized the influence of different amino acid sequences on peptide self-assembly behavior, and the structure and application of gel, hoping to help researchers find the entry point as soon as possible when designing peptide sequences, and design and develop peptide-based hydrogel materials with special functions.展开更多
Chemical modification of native peptides and proteins is a versatile strategy to facilitate late-stage diversification for functional studies.Among the proteogenic amino acids,lysine is extensively involved in posttra...Chemical modification of native peptides and proteins is a versatile strategy to facilitate late-stage diversification for functional studies.Among the proteogenic amino acids,lysine is extensively involved in posttranslational modifications and the binding of ligands to target proteins,making its selective modification attractive.However,lysine’s high natural abundance and solvent accessibility,as well as its relatively low reactivity to cysteine,necessitate addressing chemoselectivity and regioselectivity for the Lys modification of native proteins.Although Lys chemoselective modification methods have been well developed,achieving site-selective modification of a specific Lys residue remains a great challenge.In this review,we discussed the challenges of Lys selective modification,presented recent examples of Lys chemoselective modification,and summarized the currently known methods and strategies for Lys site-selective modification.We also included an outlook on potential solutions for Lys site-selective labeling and its potential applications in chemical biology and drug development.展开更多
By investigating 17 peptide arylthioesters that were previously challenging to produce,this study reveals a clear correlation between increased ligation activity and decreased pKa values of their corresponding arylthi...By investigating 17 peptide arylthioesters that were previously challenging to produce,this study reveals a clear correlation between increased ligation activity and decreased pKa values of their corresponding arylthiols.The observed differences are attributed to variations in thioester bond strength and steric hindrance.These insights have led to the development of an improved one-pot chemical protein synthesis approach that leverages the reactivity differences between peptide arylthioesters with C-terminal Ala-SPh(4-NO_(2))and Ala-S-Ph(2,6-diCH_(3)).This approach eliminates the need for thiol-thioester exchange and additive removal steps while enabling in situ desulfurization,thereby significantly simplifying the protein synthesis process.展开更多
文摘为确定凝胶电泳后条带中DNA的长度和浓度,该文提出了一种通过DNA荧光强度精确分析DNA长度及浓度的有效方法。对D2000 DNA ladder进行凝胶电泳,采集图像并进行处理。利用荧光强度与DNA浓度之间的线性关系以及迁移距离与DNA长度的线性关系进行数据分析。结果显示:采用SYBR Green I作为荧光染料电泳DNA时,图像中各像素点中的绿色与红色灰度值可以反映DNA的特征信息,且绿色灰度值明显高于红色灰度值;对于小于2000 bp的DNA片段,其分子量与迁移距离呈反比例函数关系,当二者分别取对数时,其相关系数达0.971,可用于建立DNA分子量与迁移距离的数学模型以计算DNA分子量;通过计算电泳峰峰值及电泳峰积分面积,发现对于浓度比为2∶1的两个DNA条带,二者的比值为2.16与1.96、2.11与1.94、2.16与1.93,表明电泳峰积分面积能更有效地反映DNA的真实浓度值。该研究对于核酸凝胶电泳仪的开发具有重要应用价值。
文摘肽基水凝胶作为生物活性材料在药学、纳米材料化学、组织工程等领域受到广泛关注。肽水凝胶的设计往往遵循自下而上的思路,即基于分子自组装的方法,以微观结构为基础扩展到宏观结构的形成。这种从微观角度出发的方法缺乏具体的模型阐述,初学者往往难以上手。因此,我们根据以β-折叠为基本自组装结构的肽基水凝胶的研究,总结了氨基酸对于肽自组装行为以及凝胶结构与应用的影响,期望可以帮助研究者在设计多肽序列时可以尽快地找到切入点,开发出具有特殊功能的肽基水凝胶材料。As bioactive materials, peptide-based hydrogels have attracted extensive attention in the fields of pharmacy, nanomaterial chemistry, tissue engineering, etc. The design of hydrogels often follows the bottom-up approach, that is the method based on molecular self-assembly, extending from microstructure to the formation of macrostructure. But this method from the micro-perspective lacks specific model elaboration, making it difficult to get started for beginners. Therefore, based on some studies on peptide-based hydrogels with β-sheet as the basic self-assembly structure, we summarized the influence of different amino acid sequences on peptide self-assembly behavior, and the structure and application of gel, hoping to help researchers find the entry point as soon as possible when designing peptide sequences, and design and develop peptide-based hydrogel materials with special functions.
基金the National Natural Science Foundation of China(Nos.82373722,22077144)Hunan Provincial Natural Science Foundation of China(No.2023JJ30527)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2023B1515040006)Guangdong Provincial Key Laboratory of Construction Foundation(No.2023B1212060022)Key Research and Development Program of Guangdong Province(No.2020B1111110003).
文摘Chemical modification of native peptides and proteins is a versatile strategy to facilitate late-stage diversification for functional studies.Among the proteogenic amino acids,lysine is extensively involved in posttranslational modifications and the binding of ligands to target proteins,making its selective modification attractive.However,lysine’s high natural abundance and solvent accessibility,as well as its relatively low reactivity to cysteine,necessitate addressing chemoselectivity and regioselectivity for the Lys modification of native proteins.Although Lys chemoselective modification methods have been well developed,achieving site-selective modification of a specific Lys residue remains a great challenge.In this review,we discussed the challenges of Lys selective modification,presented recent examples of Lys chemoselective modification,and summarized the currently known methods and strategies for Lys site-selective modification.We also included an outlook on potential solutions for Lys site-selective labeling and its potential applications in chemical biology and drug development.
基金CAMS Innovation Fund for Medical Sciences(CIFMS,No.2021-I2M-1-026)the National Key R&D Program of China(No.2018YFE0111400)+6 种基金the NIH Research Project Grant Program(No.R01 EB025892)the National Natural Science Foundation of China(the Training Program of the Major Research Plan,No.91853120)the National Major Scientific and Technological Special Project of China(Nos.2018ZX09711001-005 and 2018ZX09711001-013)the State Key Laboratory of Bioactive Substance and Function of Natural Medicines,Institute of Materia Medicathe Biomedical High Performance Computing Platform,Chinese Academy of Medical Sciencesthe Chinese Academy of Medical SciencesPeking Union Medical College for funding and support.
文摘By investigating 17 peptide arylthioesters that were previously challenging to produce,this study reveals a clear correlation between increased ligation activity and decreased pKa values of their corresponding arylthiols.The observed differences are attributed to variations in thioester bond strength and steric hindrance.These insights have led to the development of an improved one-pot chemical protein synthesis approach that leverages the reactivity differences between peptide arylthioesters with C-terminal Ala-SPh(4-NO_(2))and Ala-S-Ph(2,6-diCH_(3)).This approach eliminates the need for thiol-thioester exchange and additive removal steps while enabling in situ desulfurization,thereby significantly simplifying the protein synthesis process.
