Comparison of Thermal Aggregation of Bovine Immunoglobulin G subclasses

Abstract

Bovine IgG1 and IgG2 had different thermal susceptibilities depending upon pH and ionic strength. When heated at 65.degree. C for 30 min under the neutral pH conditions, IgG1 and IgG2 showed different behavior for turbidity formation. By gel filtration chromatography, IgG1 showed large peak of soluble aggregates. These differences could be due to the difference in charged conditions of IgG1 and IgG2 molecules as evidenced by the thermal stability of succinylated IgG2 relative to native IgG2. Formation of aggregates or polymers was monitored by turbidity measurements and by gel filtration chromatography.