Naso R B, Stanker L H, Kopchick J J, Ng V L, Karshin W L, Arlinghaus R B
J Virol. 1983 Mar;45(3):1200-6. doi: 10.1128/JVI.45.3.1200-1206.1983.
A glycosylated 45,000-Mr protein containing Rauscher murine leukemia virus p15 and p12 antigenic sites and tryptic peptides was identified in Rauscher murine leukemia virus-infected cells. This glycoprotein, termed gP45gag, was also shown to contain a single tryptic peptide also present in gPr80gag and its unglycosylated apoprotein precursor Pr75gag, but lacking in Pr65gag or Pr40gag. The presence of this peptide only in viral precursor proteins containing the so-called leader (L) sequence strongly suggests that gPr45gag is an N-terminal fragment of larger glycosylated gag polyproteins, composed of L sequences in addition to p15 and p12. The kinetics of appearance of radiolabeled gPr45gag and its disappearance during chase-incubation is suggestive of a precursor-like role for this intermediate gene product. An observed 27,000-Mr glycosylated polypeptide, termed gP27gag and containing p15 but not p12, p30, or p10 antigenic determinants, is a candidate cleavage product derived from gPr45gag. These observations suggest that gPr45gag and its putative cleavage product gP27gag represent an authentic pathway for intracellular processing of glycosylated core proteins.
在感染劳斯氏鼠白血病病毒的细胞中鉴定出一种糖基化的45,000道尔顿蛋白，其含有劳斯氏鼠白血病病毒p15和p12抗原位点以及胰蛋白酶肽段。这种糖蛋白，称为gP45gag，还显示含有一个单一的胰蛋白酶肽段，该肽段也存在于gPr80gag及其未糖基化的载脂蛋白前体Pr75gag中，但在Pr65gag或Pr40gag中不存在。仅在含有所谓前导（L）序列的病毒前体蛋白中存在这种肽段，强烈表明gPr45gag是较大糖基化gag多蛋白的N端片段，除了p15和p12外还由L序列组成。放射性标记的gPr45gag出现的动力学及其在追踪孵育期间的消失表明这种中间基因产物具有前体样作用。观察到的一种27,000道尔顿的糖基化多肽，称为gP27gag，含有p15但不含有p12、p30或p10抗原决定簇，是源自gPr45gag的候选裂解产物。这些观察结果表明，gPr45gag及其推定的裂解产物gP27gag代表了糖基化核心蛋白细胞内加工的真实途径。
