Determination of an Immunocontraceptive Peptide in a Wildlife Vaccine Formulation

Authors

David A. Goldade, USDA/APHIS/WS/National Wildlife Research CenterFollow
Jeffrey M. Kemp, USDA/APHIS/WS/National Wildlife Research Center
Jeanette R. O'Hare, USDA/APHIS/WS/National Wildlife Research CenterFollow
Lowell A. Miller, USDA/APHIS/WS/National Wildlife Research Center

Date of this Version

2013

Citation

Goldade, D.A., J.M. Kemp, J.R. O'Hare, and L.A. Miller. 2013. Determination of an immunocontraceptive peptide in a wildlife vaccine formulation. In G. Cobb, editor. Evaluating Veterinary Pharmaceutical Behavior in the Environment. American Chemical Society. 149-158. doi 10.1021/bk-2013-1126.ch006.

Comments

U.S. government work.

Abstract

Wildlife populations continue to grow despite the use of traditional management techniques. GonaCon™ Immunocontraceptive Vaccine is a vaccine used to reduce reproduction in mammalian species, including white-tailed deer (Odocoileus virginianus). The vaccine consists of synthetic gonadotropin releasing hormone (GnRH) conjugated to a mollusk hemocyanin (Concholepas concholepas) prepared as an emulsion with mineral oil to promote a prolonged immune response. Development of an analytical method for determination of the active ingredient in the vaccine formulation was complicated by the emulsion and conjugation of GnRH to the carrier protein. Breaking the emulsion was achieved chemically by addition of diethyl ether. The aqueous portion containing the GnRH conjugate was cleaved enzymatically with a protease (clostripain) at the arginine-proline site of its peptide sequence. Hydrolysis produced a diagnostic eight amino acid peptide fragment which was unique to GnRH and easily quantified by LC/MS/MS. Typical recoveries of fortified samples at the target concentration exceeded 90%.