Costae of Tritrichomonas foetus: purification and chemical composition.

The costa is an intracellular organelle common to all trichomonads. Costae from Tritrichomonas foetus have been purified by a method which involves lysis of T. foetus with the heat-stable hemolysin produced by Pseudomonas aeruginosa, followed by differential centrifugation. Analysis of the purified costae demonstrated that the organelle is composed of 95 percent carbohydrate and 5 percent protein. The carbohydrate moiety, probably a polysaccharide, consisted of glucose (95 percent), mannose (0.4 percent), glucosamine (1.4 percent), ribose (0.6 percent), and an unidentified sugar (2.6 percent). The kinetosomal complex was attached to the costa after initial lysis of cells but was separated from the costa during purification.

Identification of a mouse monoclonal antibody, LHLP-1, specific for human Lp(a).

Heretofore, immunologic reagents used to define and quantify human Lp(a) have been polyclonal in origin and therefore heterogeneous in antigenic specificity. We report here the isolation of a mouse monoclonal antibody, LHLP-1, monospecific for Lp(a). The antigen reactive with LHLP-1 was expressed in both lipoprotein Lp(a) as well as apolipoprotein Lp(a) delipidated by SDS treatment; however, disulfide reduction of apolipoprotein Lp(a) inhibited LHLP-1 reactivity. The antigen reactive with LHLP-1 on Lp(a), therefore, appears not to require lipid for expression of its conformationally dependent (disulfide-inhibitable) epitope. Antigen reactivity was virtually absent in the apoB and other proteins contained in very low density, low density, and high density lipoprotein particles. Immunologic quantification of Lp(a) in individual serum samples with a rabbit reference antiserum or LHLP-1 showed good correlation. We conclude that the monoclonal antibody LHLP-1 identifies an antigen unique to Lp(a) and that this antibody may therefore be useful in the further characterization and measurement of human Lp(a).