Catalytic Antibodies Generated via Homologous and Heterologous Immunization
摘要:
Two different immunization protocols using haptens 1 and 2 have been employed for the generation of catalytic antibodies capable of hydrolyzing ester 3. Three successive injections with one hapten 1 or 2, a protocol referred to as homologous immunization, provided hydrolytic antibodies with a rate acceleration in the range of 10(3)-10(4). These antibodies exhibited inhibitory activity only by the hapten used for the immunization. On the other hand, two successive injections with hapten 1 followed by a boost with hapten 2, a protocol referred to as heterologous immunization, induced catalytic antibodies with a rate acceleration up to 1.5 x 10(5). The majority of these catalytic antibodies possessed cross-reactivities to haptens 1 and 2, and the catalytic activities were effectively inhibited by both haptens. Control experiments have suggested that catalytic antibodies via heterologous immunization are derived through the unique stimulation of 1-primed memory B-cells by the secondary hapten 2, but not through the primary response of virgin B-cells by 2. Two catalytic antibodies H2-23 and H5H2-42, generated via homologous immunization with 2 and heterologous immunization with haptens 1 and 2, respectively, were selected for the detailed kinetic studies. Antibody H2-23 showed burst kinetic behavior and the burst phase was eliminated by the addition of p-nitrophenolate 5. Antibody H5H2-42 has no burst phase and exhibited high multiple turnover activity. The pH-dependent kinetic characterization of H5H2-42 suggested that bifunctional catalytic residues in the antibody combining site likely exist in the active site. These results imply that the heterologous immunization strategy offers a potential means of introducing multiple catalytic residues into antibody combining sites without recourse to complicated synthesis of multifunctional haptens.
Substrate attenuation: An approach to improve antibody catalysis
作者:Kim D. Janda、Stephen J. Benkovic、Donald A. McLeod、Diane M. Schloeder、Richard A. Lerner
DOI:10.1016/s0040-4020(01)81784-1
日期:1991.1
Antibodies raised to quinaldine phosphonamide 1a showed no ability to hydrolyze its most homologous substrates amide and ester 2 and 3, respectively. However, within this same set of antibodies some thirteen showed a great propensity to hydrolyse a structurally similar naphthyl ester In addition to heteroatom discrimination one of the antibodies examined in detail displayed an increase in catalytic efficiency presumably via weak apparent binding (k(m)) when phenylesters were employed as substrates. These findings suggest abzyme catalysis may be improved via substrate attenuation.
A Simple Protocol for the Modular Assembly of“Millipede” Artificial Enzymes
作者:William B. Motherwell、Catherine E. Atkinson、Abil E. Aliev、Stephanie Y. F. Wong、Brian H. Warrington
DOI:10.1002/anie.200352370
日期:2004.2.27
Immobilized catalytic antibodies in aqueous and organic solvents
作者:Kim D. Janda、Jon A. Ashley、Teresa M. Jones、Donald A. McLeod、Diane M. Schloeder、Michael I. Weinhouse
DOI:10.1021/ja00180a035
日期:1990.11
Suga; Ersoy; Williams, Journal of the American Chemical Society, 1994, vol. 116, # 13, p. 6025 - 6026
Substituent effects of an antibody-catalyzed hydrolysis of phenyl esters: further evidence for an acyl-antibody intermediate
作者:Richard A. Gibbs、Patricia A. Benkovic、Kim D. Janda、Richard A. Lerner、Stephen J. Benkovic
DOI:10.1021/ja00035a057
日期:1992.4
The hydrolysis of a series of para-substituted phenyl esters by the monoclonal catalytic antibody NPN43C9 has been investigated. The apparent pK a observed in the k cat /K m -pH profiles shifts from 8.9 (p-nitrophenyl ester) up to a maximum of 9.5 (p-methylphenyl ester). A correlation of the antibody-catalyzed rates of hydrolysis of the esters versus the σ parameter affords a ρ value of 2.3, indicative
已经研究了单克隆催化抗体 NPN43C9 对一系列对位取代苯基酯的水解。在 k cat /K m -pH 曲线中观察到的表观 pK a 从 8.9(对硝基苯酯)移至最大值 9.5(对甲基苯酯)。抗体催化的酯水解速率与 σ 参数的相关性提供 2.3 的 ρ 值,表明水解机制通过中性氮亲核试剂的攻击进行,与一般碱催化的低 ρ 值形成对比水解