Methoxypoly(ethylene glycol)-conjugated carboxypeptidase A for solid tumor targeting: part I: synthesis and characterization.
Methoxypoly(ethylene glycol)-conjugated carboxypeptidase A for solid tumor targeting: part I: synthesis and characterization.
复制标题
用于实体瘤靶向的甲氧基聚（乙二醇）缀合的羧肽酶 A：第一部分：合成和表征。
DOI：
10.1016/j.jconrel.2005.01.016
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Kwon,GlenS
中科院分区：
文献类型：
--
作者：
Ton,GiangthyN;Fine,JasonP;Kwon,GlenS
新型抗癌剂的体内功效已经由于不能将有效浓度的药物递送至肿瘤而受到阻碍。使用大分子如抗体和聚合物将酶递送至肿瘤已经揭示，催化无毒前药转化成其细胞毒性形式可以在肿瘤部位产生有效水平的细胞毒性剂。本研究主要集中在合成和表征甲氧基聚乙二醇修饰的羧肽酶A（CPA）的实体瘤靶向。通过连接确定数量的mPEG部分，CPA的分子量已成功从35 kDa改变为40-50 kDa。相对纯的mPEG-CPA共轭物含有一个，两个和三个mPEG链，获得在制备规模的数量，通过控制PEG化，然后通过分馏，涉及尺寸排阻色谱。在mPEG-CPA偶联物中，观察到对马尿酰-l-苯丙氨酸（hippp-l-phe）的kcat和kcat/Km的动力学性质的增强。Vmap的增加被认为是这种增强的原因。附接的mPEG到CPA大大提高了酶的稳定性相对于特定的肽酶活性对模型基板。这一发现对于开发新型CPA/甲氨蝶呤-α-肽系统用于实体瘤化疗特别重要。
In vivo efficacy of novel anticancer agents has been hindered by the inability to deliver effective concentrations of drugs to tumors. The use of macromolecules such as antibodies and polymers for enzyme delivery to tumors has revealed that catalyzing the conversion of a nontoxic prodrug into its cytotoxic form can generate an effective level of cytotoxic agents at tumor sites. This study primarily focuses on the synthesis and characterization of methoxypoly(ethylene glycol)-modified carboxypeptidase A (CPA) for solid tumor targeting. The molecular weight of CPA has been successfully altered from 35 to 40–50 kDa via attachment of a defined number of mPEG moieties. Relatively pure mPEG–CPA conjugates containing one, two, and three mPEG chains were obtained at preparative scale quantities through controlled PEGylation followed by fractionation that involved size-exclusion chromatography. An enhancement in kinetic properties including kcatand kcat/Kmtowards hippuryl-l-phenylalanine (hipp-l-phe) was observed in mPEG–CPA conjugates. An increase in the Vmappeared to be responsible for this enhancement. The attachment of mPEG to CPA substantially improved the stability of the enzyme with respect to the specific peptidase activity toward the model substrate. This finding is particularly important in the development of a novel CPA/methotrexate-α-peptide system in solid tumor chemotherapy.