Sharifi B G, Bascom C C, Johnson T C
Biochem Biophys Res Commun. 1986 Feb 13;134(3):1350-7. doi: 10.1016/0006-291x(86)90398-0.
A sialoglycopeptide inhibitor, isolated from bovine cerebral cortex cells, that reversibly inhibits protein and DNA synthesis, was coupled to either Sepharose or polyacrylamide beads. Whereas over 1 ng of the inhibitor was released from Sepharose beads after 30 min at 37 degrees C, less than 0.2 ng of the sialoglycopeptide was released from the polyacrylamide beads. When added to 3T3 cells, the immobilized sialoglycopeptide efficiently inhibited protein synthesis. No detectable sialoglycopeptide inhibitor was released into the assay medium in the presence or absence of 3T3 cells. Addition of [125I]sialoglycopeptide, coupled to acrylamide P100 beads, to 3T3 cells also demonstrated that the sialoglycopeptide was not internalized by the cells. Thus we conclude that an interaction of the sialoglycopeptide at the cell surface is sufficient for biological inhibitory activity.
一种从牛大脑皮层细胞中分离出的唾液酸糖肽抑制剂，它能可逆地抑制蛋白质和DNA合成，该抑制剂与琼脂糖或聚丙烯酰胺珠偶联。在37℃下30分钟后，超过1纳克的抑制剂从琼脂糖珠中释放出来，而从聚丙烯酰胺珠中释放的唾液酸糖肽不到0.2纳克。当添加到3T3细胞中时，固定化的唾液酸糖肽能有效抑制蛋白质合成。在有或没有3T3细胞的情况下，均未检测到唾液酸糖肽抑制剂释放到测定培养基中。将与丙烯酰胺P100珠偶联的[125I]唾液酸糖肽添加到3T3细胞中也表明，该唾液酸糖肽不会被细胞内化。因此我们得出结论，唾液酸糖肽在细胞表面的相互作用足以产生生物抑制活性。
