Development and Validation of an Antibody for Detection of Lysine Homocysteinylation in Cobalamin Disorders

The U.S. Government, through the National Institutes of Health Office of Loan and Assistance Operations under the Department of Health and Human Services, is seeking a small business contractor to develop and validate a novel polyclonal antibody targeting N-homocysteine-lysine (N-homocysteinylation), a post-translational modification currently lacking any commercial antibody reagent. This effort directly supports biomedical research into rare genetic cobalamin disorders, particularly those involving the MMACHC gene, by enabling the detection and study of this pathological modification in model systems. The contractor will synthesize and purify customized peptide antigens containing N-homocysteinylated lysine residues alongside unmodified control peptides, conjugate them to KLH carrier proteins, and immunize rabbits to generate polyclonal sera. Multiple serum samples will be collected prior to and following antigen boosts, with rigorous testing conducted on N-homocysteinylated proteins derived from established mouse models of MMACHC deficiency and through ELISA screening against both modified and unmodified peptides to ensure specificity and efficacy. The project culminates in a terminal bleed and purification of the final working antibody, which will be used to identify and characterize the proteins affected by this aberrant modification, thereby advancing the understanding of disease mechanisms and paving the way for future targeted therapies. The solicitation, identified as 75N98026Q00506 and posted on June 3, 2026, is a presolicitation action with a response deadline of June 13, 2026, and is designated as a Total Small Business Set-Aside under FAR 19.5, limiting eligibility to small businesses as defined by the SBA. The project falls under NAICS code 541714 for biomedical research services and will be performed in Bethesda, Maryland, with the point of contact being John Burton at the NIH. While the technical scope is clearly defined with specific steps for antigen design, immunization, testing, and antibody purification, the solicitation does not specify delivery schedules, cost structures, evaluation criteria, inspection standards, packaging requirements, or formal contract administration details. The absence of these elements indicates the presolicitation nature of the document, intended primarily to gather industry interest and technical feasibility input prior to formal contract award. No attachments, special requirements, or representations beyond the set-aside status are detailed in the available information.