- 作者: 竇慶平 ; 陳光宇
- 作者服務機構: Dept. of Chemistry, Rutgers, State Univ. of New Jersey, New Brunswick, New Jersey, U.S.A.
- 中文摘要: Incubation of various cultured mammalian cells under growth-stimulatory condition with .lbrak./sup 3/H.rbrak. putrescine or .lbrak./sup 3/H.rbrak. spermidine results in a labeling of an 18,000-dalton protein. The labeling is due to post- translational conversion of a lysine residue to hypusine residue, using the butylamino moiety derived from spermidine. In order to search for an abundant source for the purification of this protein, we have examined possible existence of this hypusine-containing 18,000-dalton protein(hyp-18k) in chick embryos by the metabolic labeling method. Metabolic labeling of chick embryo fibroblasts, prepared from the Day 11 embryos, by .lbrak./sup 3/H.rbrak. putrescine resulted in two prominently labeled protein bands, Mr=18,000 and 20,000, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. Two-dimensional gel analysis indicated that the labeled 20,000-dalton protein had a pI value of 5.5 and the labeled 18,000-dalton protein exhibited isoform structures with pI values ranging from 4.6 to 5.1. Peptide map analysis showed that these two proteins are similar but not identical. Both labeled proteins contained radioactive hypusine residue and exhibited strong binding to Cibacron Blue dye. The time course of the metabolic labeling of these two proteins, however, differed dramatically. The labeling of the 18,000-dalton protein appeared early and continued to increase 24 h after serum stimulation. In contrast, the labeling of the 20,000-dalton protein became prominent only after much longer period of incubation.
- 英文摘要: --
- 中文關鍵字: Hypusine-Containing Proteins; Polyamines; Chick Embryo; Metabolism
- 英文關鍵字: /sup 3/H-蛋白質;多胺類;雞胚;代謝