Production of a High Affinity Antibody Specific to the Calcium-Free-Form of Calmodulin, Using N-Acetyl-muramyl-L-alanyl-D-isoglutamine-calmodulin Conjugate

Abstract

Covalent coupling of N-acetyl-muramyl-L-alanyl-D—isoglutamine (MDP) to calmodulin was used in order to enhance its immunogenicity. Rabbit antibodies against calmodulin were obtained, interacting with the calcium-free-form of calmodulin. The radioimmunoassay was developed using the whole sera (titre 1:20,000) having a sensitivity of 20 pg per tube (50% displacement 500 pg/ assay tube). The radioimmunoassay shows the same concentrations of calmodulin in rat brain homogenate (4.9 ± 0.86 μg/mg protein), bovine neurosecretosomes (0.77 ± 0.10 μg/mg protein), and bovine neurohypophysial secretory vesicles (0.05 ± 0.01 μg/mg protein) as the phosphodiesterase activation method.