Kinetics and thermodynamics of dimer formation and dissociation for a recombinant humanized monoclonal antibody to vascular endothelial growth factor
Kinetics and thermodynamics of dimer formation and dissociation for a recombinant humanized monoclonal antibody to vascular endothelial growth factor
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DOI：
10.1021/bi9905516
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发表时间：
1999-10-19
期刊：
影响因子：
2.9
通讯作者：
Cromwell, MEM
中科院分区：
文献类型：
--
作者：
Moore, JMR;Patapoff, TW;Cromwell, MEM
The recombinant humanized antibody (rhuMAb) VEGF has a high affinity for vascular endothelial growth factor and is currently being evaluated in clinical trials as a cancer therapeutic. Under acidic pH and low ionic strength conditions, the antibody was predominantly present as monomer. Under physiological conditions, the appearance of significant amounts of a noncovalent, reversible dimer were observed by size-exclusion chromatography. The kinetics and thermodynamics of the reversible self-association for rhuMAb VEGF monomer were investigated as a function of pH, temperature, and ionic strength by size-exclusion chromatography using the concentration jump method. The rate constant for dimer formation ranged 23-112 M-1 min(-1) under the conditions studied, values that are significantly lower than those reported in the literature for other proteins that self-associate. The rate constant for dissociation ranged 0.0039-0.021 min(-1). Gibbs' free energies, enthalpies, entropies, and activation energies were determined and revealed that dimer formation is optimal at pH 7.5-8.0, which may be reflective of charge shielding occurring near the pi of the protein. There was a negative change in entropy for dissociation (values from -18.1 to -12.8 cal/mol K), In the presence of D2O or 1 M NaCl, dimerization was enhanced. The results of the kinetic and thermodynamic analysis of this study indicate that rhuMAb VEGF dimerization occurs primarily through hydrophobic interactions.
