Production and characterization of the monoclonal antibody against SGP120, a novel serum protein

A monoclonal antibody designated B1.9.E-2 was produced and characterized to facilitate study of the immunizing antigen—a serum glycoprotein of 120 kDa (sgp 120) of unknown function. The antibody, produced in mice, reacts with 1-2 epitopes located in the N-terminal region of the sgp 120 molecule. The affinity of the reaction, as determined by Scatchard analysis, is Ka = 1.13 × 1010 1/M and is of a hydrophobic nature. The monoclonal antibody can be purified to a high degree by a modified caprylic acid method and by protein G FPLC chromatography column. B1.9.E-2 does not trigger the complement cascade, as determined by C3 RIA and immune complex solubilization assays. Both affinity purified (C4b Sepharose) and chromatographically isolated (using jacqualine agarose) sgp 120 were recognized by B1.9.E-2. The monoclonal antibody can be utilized for affinity purification of sgp 120, for detection of intact or cleaved sgp 120 in biological samples of healthy and ill individuals, and for the number of functional and...