Rabbit Heart Fatty Acid-Binding Protein Isolation, Characterization, and Application of a Monoclonal Antibody

Knowlton, Anne A.
Burner, Robert E.
Brecher, Peter

Cardiac Muscle Research Laboratory, Cardiovascular Institute, and the Biochemistry Department, Boston University School of Medicine, and the Cardiology Section and the Thorndike Memorial Laboratory, Boston City Hospital, Boston, Massachusetts.

Address for correspondence: Anne A. Knowlton, MD, Boston University School of Medicine, R-215, 80 East Concord St., Boston, MA 02118.

Received December 1, 1988; accepted April 20, 1989.

Circulation Research 65(4):p 981-988, October 1989.

A fatty acid-binding protein (FABP) was purified from rabbit heart and characterized with respect to size, isoelectric point, and tissue distribution. This protein was found in red muscle, diaphragm, and aorta, as well as in the heart. Amino acid composition of rabbit heart FABP differed only slightly from the human and rat proteins. Rabbit heart FABP was shown to bind two molecules of fatty acid. A monoclonal antibody was developed and used to demonstrate the feasibility of a one-step purification with affinity chromatography. Cross-reactivity was found between the human protein and the rabbit antibody, and an immunoassay was developed to human heart FABP. Levels of human heart FABP in the plasma of patients with acute myocardial infarction were significantly elevated (83 ± 9 μg/ml) compared with patients with pulmonary edema (52 ± 7 μg/ml) and normal volunteers (28 ± 5 μg/ml; p < O.OS, mean ± SEM).