Ligand Recognition by E- and P-Selectin: Chemoenzymatic Synthesis and Inhibitory Activity of Bivalent Sialyl Lewis x Derivatives and Sialyl Lewis x Carboxylic Acids
摘要:
Described is the preparation of five sLe(x) dimers and five sLe(x) carboxylic acids by coupling chemoenzymatically synthesized amino-substituted sialyl Lewis x (sLe(x)) derivative 4 to homobifunctional cross-linkers 20-24 of varying chain length. 20-24 were obtained by alkylating low-molecular-weight oligoethylene glycols with tert-butyl bromoacetate and subsequent transformation of the di-tert-butyl esters into disuccinimide esters. The products were assayed for inhibition against binding of a sLe(a)-polymer to immobilized E- and P-selectin. In the E-selectin assay all dimers had lower IC50 values than the sLex monomer. The results show that comparable binding enhancements can be obtained with linkers of completely different length and rigidity. In the P-selectin assay four of the five sLe(x) carboxylic acids displayed significantly improved inhibitory potency. The lowest IC50 value was observed for the compound with the shortest spacer between the sLex moiety and the additional carboxylate, being ca. 20-40 times more potent than unmodified sLex. These findings should be of importance for the design of new multivalent forms of sLe(x) as well as sLe(x) mimetics as high-affinity selectin ligands.
Ligand Recognition by E- and P-Selectin: Chemoenzymatic Synthesis and Inhibitory Activity of Bivalent Sialyl Lewis x Derivatives and Sialyl Lewis x Carboxylic Acids
摘要:
Described is the preparation of five sLe(x) dimers and five sLe(x) carboxylic acids by coupling chemoenzymatically synthesized amino-substituted sialyl Lewis x (sLe(x)) derivative 4 to homobifunctional cross-linkers 20-24 of varying chain length. 20-24 were obtained by alkylating low-molecular-weight oligoethylene glycols with tert-butyl bromoacetate and subsequent transformation of the di-tert-butyl esters into disuccinimide esters. The products were assayed for inhibition against binding of a sLe(a)-polymer to immobilized E- and P-selectin. In the E-selectin assay all dimers had lower IC50 values than the sLex monomer. The results show that comparable binding enhancements can be obtained with linkers of completely different length and rigidity. In the P-selectin assay four of the five sLe(x) carboxylic acids displayed significantly improved inhibitory potency. The lowest IC50 value was observed for the compound with the shortest spacer between the sLex moiety and the additional carboxylate, being ca. 20-40 times more potent than unmodified sLex. These findings should be of importance for the design of new multivalent forms of sLe(x) as well as sLe(x) mimetics as high-affinity selectin ligands.
Multimeric Cyclic RGD Peptides as Potential Tools for Tumor Targeting: Solid-Phase Peptide Synthesis and Chemoselective Oxime Ligation
作者:Georgette Thumshirn、Ulrich Hersel、Simon L. Goodman、Horst Kessler
DOI:10.1002/chem.200204304
日期:2003.6.16
angiogenesis. Targeting this receptor may provide information about the receptor status of the tumor and enable specific therapeutic planning. Solid-phasepeptidesynthesis of multimeric cyclo(-RGDfE-)-peptides is described, which offer the possibility of enhanced integrin targeting due to polyvalency effects. These peptides contain an aminooxy group for versatile chemoselectiveoximeligation. Conjugation
alpha v beta 3整合素受体在人类转移和肿瘤诱导的血管生成中起重要作用。靶向该受体可以提供有关肿瘤的受体状态的信息,并可以进行特定的治疗计划。描述了多聚环(-RGDfE-)-肽的固相肽合成,由于多价效应,其提供了增强整联蛋白靶向性的可能性。这些肽含有一个氨基氧基,可进行通用的化学选择性肟连接。与对三甲基锡烷基苯甲醛结合产生放射性碘十二烷甲酰化的前体,这将使它们可用作靶向和成像表达αv beta 3的肿瘤细胞的潜在工具。不需要保护策略并且在温和条件下以高收率获得了缀合物。
Ligand Recognition by E- and P-Selectin: Chemoenzymatic Synthesis and Inhibitory Activity of Bivalent Sialyl Lewis x Derivatives and Sialyl Lewis x Carboxylic Acids
作者:Valentin Wittmann、Shuichi Takayama、Ke Wei Gong、Gabriele Weitz-Schmidt、Chi-Huey Wong
DOI:10.1021/jo980350s
日期:1998.7.1
Described is the preparation of five sLe(x) dimers and five sLe(x) carboxylic acids by coupling chemoenzymatically synthesized amino-substituted sialyl Lewis x (sLe(x)) derivative 4 to homobifunctional cross-linkers 20-24 of varying chain length. 20-24 were obtained by alkylating low-molecular-weight oligoethylene glycols with tert-butyl bromoacetate and subsequent transformation of the di-tert-butyl esters into disuccinimide esters. The products were assayed for inhibition against binding of a sLe(a)-polymer to immobilized E- and P-selectin. In the E-selectin assay all dimers had lower IC50 values than the sLex monomer. The results show that comparable binding enhancements can be obtained with linkers of completely different length and rigidity. In the P-selectin assay four of the five sLe(x) carboxylic acids displayed significantly improved inhibitory potency. The lowest IC50 value was observed for the compound with the shortest spacer between the sLex moiety and the additional carboxylate, being ca. 20-40 times more potent than unmodified sLex. These findings should be of importance for the design of new multivalent forms of sLe(x) as well as sLe(x) mimetics as high-affinity selectin ligands.