Monoclonal antibody conjugates of doxorubicin prepared with branched peptide linkers: Inhibition of aggregation by methoxytriethyleneglycol chains
Monoclonal antibody conjugates of doxorubicin prepared with branched peptide linkers: Inhibition of aggregation by methoxytriethyleneglycol chains
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DOI：
10.1021/jm020149g
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发表时间：
2002-09-12
影响因子：
7.3
通讯作者：
Trail, PA
中科院分区：
文献类型：
--
作者：
King, HD;Dubowchik, GM;Trail, PA
高摩尔比的BR 96免疫缀合物是使用支链肽-多柔比星接头合成的，所述支链肽-多柔比星接头被设计成在抗原特异性内化到溶酶体中之后释放多柔比星。然而，这些免疫缀合物高度倾向于非共价的二聚体聚集。我们假设这是由于（1）肽的疏水性，（2）在阿霉素的3 '-氨基形成酰胺时失去正电荷，和（3）肽疏水残基的接近形成有效的分子间堆积相互作用。通过将亲水性甲氧基三甘醇链引入到分支肽接头的阿霉素部分上，已经消除或大大减少了免疫缀合物产物中的聚集。甲氧基三甘醇链通过在pH 7下稳定但在pH 5下快速水解以释放游离药物的腙键与接头的多柔比星部分连接。由甲氧基三甘醇修饰的支链肽-多柔比星接头合成的BR 96免疫缀合物在体外是高度有效的和免疫特异性的。数据表明，甲氧基三甘醇链在体外抗原特异性内化到肿瘤溶酶体中时如设计的那样水解，其中肽接头的酶促降解释放游离多柔比星。
High mole ratio BR96 immunoconjugates were synthesized using branched peptide-doxorubicin linkers designed to liberate doxorubicin following antigen-specific internalization into lysosomes. However, these immunoconjugates are highly prone to noncovalent, dimeric aggregation. We hypothesize that this is due to (1) the hydrophobic nature of the peptides, (2) the loss of positive charge upon amide formation At the 3'-amino group of doxorubicin, and (3) the proximity of the peptide hydrophobic residues to form efficient intermolecular stacking interactions. By introducing a hydrophilic methoxytriethylene glycol chain onto the doxorubicin portion of the branched peptide linkers, aggregation has been eliminated or greatly reduced in the immunoconjugate products. The methoxytriethylene glycol chain was linked to the doxorubicin moiety of the linker via a hydrazone bond that is stable at pH 7 but hydrolyzes rapidly at pH 5 to release free drug. BR96 immunoconjugates synthesized from methoxytriethylene glycol-modified branched peptide-doxorubicin linkers are highly potent and immunospecific in vitro. The data suggest that the methoxytriethylene glycol chain hydrolyzes as designed upon antigen-specific internalization into tumor lysosomes in vitro, where enzymatic degradation of the peptide linker releases free doxorubicin.