军事医学2024，Vol.48Issue(10)：753-759,7.DOI:10.7644/j.issn.1674-9960.2024.10.005
反应体系pH对聚乙二醇牛血红蛋白偶联物性质的影响
Effect of pH value of reaction system on properties of pegylated bovine hemoglobin conjugate
常琛 1尤国兴 1王巍 2李伟丹 1王瑛 1朱凯 1周虹 1赵莲 1陈玉芝1
作者信息
- 1. 军事科学院军事医学研究院,北京 100850
- 2. 解放军总医院第四医学中心,北京 100089
- 折叠
摘要
Abstract
Objective To explore the impact of pH value of the reaction system on the properties of bovine hemoglobin modified with aldehydeated polyethylene glycol(PEG-bHb).Methods PEG-bHb conjugates were synthesized under varying pH conditions(6.0,6.5,7.4 and 8.0)of the reaction system while consistent molar ratios,temperature,and reaction time were maintained.The structural and functional attributes of PEG-bHb were characterized.Results The proportion of methemoglobin decreased with an increase in pH.In a weakly acidic reaction environment,the PEG-bHb was found to be relatively highly modified.At pH 6.5,the average number of PEG chains attached to the bHb surface was 6.86±0.38.Selective PEG modification of the N-terminal α-NH2 groups was more pronounced under weakly acidic conditions.Specifically,at pH 6.5,the modification efficiency of the N-terminal α-NH2 groups of bHb by aldehyde-activated PEG reached 95.4％for the α-chains and 99.3％for the β-chains.The PEG modification influenced the heme region microenvi-ronment of bHb,with minimal structural impact observed at pH 6.5.After modification,the oxygen affinity of PEG-bHb was enhanced,the Hill coefficient was reduced,and there were significant increases in colloid osmotic pressure,viscosity,and particle size,all of which differed markedly from the unmodified bHb group(P＜0.001).Conclusion The synthesis of PEG-bHb under weakly acidic conditions can result in a high degree of selective modification of the N-terminal α-NH2 groups and an overall high degree of modification.关键词
红细胞代用品/聚乙二醇/牛血红蛋白/选择性修饰Key words
red blood cell substitutes/polyethylene glycol/bovine hemoglobin/selective modification分类
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常琛,尤国兴,王巍,李伟丹,王瑛,朱凯,周虹,赵莲,陈玉芝..反应体系pH对聚乙二醇牛血红蛋白偶联物性质的影响[J].军事医学,2024,48(10):753-759,7.
