Monoclonal antibodies to bovine parathyroid hormone: production and characterization

1. This paper describes the production and characterization of monoclonal monoclonal antibodies against bovine parathyroid hormone (bPTH) - (1-84). 2. Spleen cells from A/J mice successfully immunized with bPTH-(1-84) were fused with SP2/O myeloma cells using PEG 4000 as fusogen. The screening method employed microtiter plates coated with sheep antimouse IgG and the presence of specific monoclonal antibodies was demonstrated by the binding of 125I-bPTH-(1-84). 3. A delailed study of the specificity of the three viable monoclonals with highest affinity showed that two (6FH6 and 6CD4) were amino-terminal specific and the other (5BG9) carboxyl-terminal specific. The two amino-terminal monoclonal antibodies appear to recognize the same antigenic site. 4. The monoclonal antibodies produced are potentially useful reagents for the development of new methods for the measurement of PTH in biological fluids, studies on the interaction of PTH with its receptor, as well as localization of PTH producing cells

Characterization of a high-affinity antiserum specific for the amino-terminal sequence of human parathyroid hormone

1. The present paper describes a detailed study of the specificity of high-affinitu antibodies obtained from the yolk of eggs laid by achicken successfully immunized with synthetic human parathyroid hormone (hPTH)-(1-34). 2. Using 125I-labelled bovine parathyroide hormone (bPTH)-(1-84) puridied by high performance liquid chromatography (HPLC) as tracer, and hPTH-(1-34) as reference, we found superimposable curves with hPTH-(13-34), bPTH-(13-34) and bTH-(1-34); the [Asp-76]hPTH-(1-84) peptide showed a molar percent cross-reactivity (calculated at 50% B/BO) of 73% and the bovine sequence 1-84 of 15%. 3. Studying amidated [Tyr-34] bovine PTH fragments we found the highest cross-reactivity with the peptide 7-34 (1.7%) and 25-34 (0.4%). The bovine sequence 1-25 showed a low reactivity (0.7%) and the 1-12 sequence none at all . Rat parathyroid hormone (rPTH)- (1-34) showed low cross-reactivity (3.1%), the same occuring with peptide [Tyr-34, Norleu-8,18]bPTH-(1-34) (1.5%). 4. The data suggest that the antibodies studied recognize epitopes in or near amino acids 18 to 25 of the sequence of the hPTH molecule. This region of the molecule is coincident with the antigenic determinant predicted by the abalysis of the hydrophilicity plot of the hPTH-(1-34) peptide

Identification of an antigenic determinant in the amino-terminal sequence of parathyroid hormone

The application of a hydrophilicity plot to define an antigenic determinat in the amino terminal sequence of human parathyroid hormone is reported. The data obtained were compared to specificity studies of three antibodies, one polyclonal and two monoclonal, against the same portion of the molecule. Result were coincident. These data support the use of the hydrophilicity plot in the prediction of antigenic sites in the parathyroid hormone molecule