Interaction of [125I]? nerve growth factor with acidic proteins

Abstract

We have demonstrated that the β nerve growth factor will interact with various acidic proteins apparently nonspecifically. When¹²⁵I-labeled β nerve growth factor at a concentration of 3.8×10⁻¹⁰ M is incubated with an acidic protein at 2 mg/ml (4.5×10⁻⁶–4.4×10⁻⁵ M), a complex is formed. This complex changes the isoelectric point of the¹²⁵I-labeled β nerve growth factor sufficiently so that the¹²⁵I-labeled β nerve growth factor migrates anomalously in polyacrylamide gel electrophoresis. The interaction between β nerve growth factor and bovine serum albumin, which appears to be complex, may be the cause of the previously reported activation of the β nerve growth factor when bovine serum albumin is present in a typical bioassay.