Malemud C J, Kresina T F
Agents Actions Suppl. 1986;18:109-16. doi: 10.1007/978-3-0348-7684-1_15.
The fine epitope specificity of two murine monoclonal antibodies (HP 2G2 and HP 4D3)1 raised against rabbit xiphoid cartilage proteoglycan monomer (fraction AlDlDl) was determined by solid-phase radioimmune assay utilizing native and heat-denatured (50 degrees C, 30 min) AlDlDl as antigen. Competitive inhibition assays using trypsin-digested native AlDlDl fragments resolved by DEAE-cellulose chromatography and isopycnic CsCl density gradient ultracentrifugation showed that HP 2G2 reacted with a recurring epitope on the core protein, whereas HP 4D3 reacted with intact native and heat-denatured AlDlDl, but not tryptic peptides of AlDlDl. However, HP 4D3 was competitively inhibited from binding to native intact AlDlDl by the clostripain limit digestion products of AlDlDl partially purified by Sepharose CL-2B chromatography. HP 4D3 when added to rabbit but not human chondrocytes in culture affected the incorporation of 35SO4 into proteoglycans found in the most dense CsCl density gradient fraction (A1) under associative conditions.
通过使用天然和热变性（50摄氏度，30分钟）的A1D1D1作为抗原的固相放射免疫测定法，确定了两种针对兔剑突软骨蛋白聚糖单体（组分A1D1D1）产生的鼠单克隆抗体（HP 2G2和HP 4D3）的精细表位特异性。使用经DEAE - 纤维素色谱和等密度CsCl密度梯度超速离心分离的胰蛋白酶消化的天然A1D1D1片段进行的竞争性抑制试验表明，HP 2G2与核心蛋白上的一个重复表位反应，而HP 4D3与完整的天然和热变性A1D1D1反应，但不与A1D1D1的胰蛋白酶肽段反应。然而，通过Sepharose CL - 2B色谱部分纯化的A1D1D1的梭菌蛋白酶极限消化产物竞争性抑制了HP 4D3与天然完整A1D1D1的结合。在缔合条件下，当将HP 4D3添加到培养的兔软骨细胞而非人软骨细胞中时，会影响35SO4掺入到在最致密的CsCl密度梯度级分（A1）中发现的蛋白聚糖中。
