The degradation of normal and analogue-containing proteins in MRC-5 fibroblasts.
Proteins containing the arginine analogue canavanine were degraded much more quickly in MRC-5 fibroblasts than those containing only normal amino acids. The degradation of both classes of protein could be well described by a pair of exponential curves, the first representing an early rapid degradation and the second, a slower phase. There were no general trends in the variation with passage number of the cells' ability to degrade either normal or analogue-containing proteins, as judged by the half-lives of proteins. But there was an increase in the proportion of labelled normal protein falling into the early rapid degradation phase as the cells senesced in culture.
D002172:Canavanine / Q000378:metabolism*; D002453:Cell Cycle; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D011506:Proteins / Q000378:metabolism*; D014633:Valine / Q000378:metabolism
D011506:Proteins; D002172:Canavanine; D014633:Valine