Surface hydrophobicity, arginylation and degradation of cytosol proteins from rat hepatocytes.
In vitro 14C-prelabelled cytosol proteins from rat hepatocytes were incubated with [3H]arginyl-tRNA in ATP-Tris-Mg-KCl-dithioerithrol medium and arginyltransferase, subsequently treated with RNase A, and the double-labelled proteins were isolated by gel filtration. The affinity of these [3H]arginylated-14C-labelled cytosol proteins to hydrophobic surfaces was investigated with octyl-Sepharose, phenyl-Sepharose and with FPLC on phenyl-Superose (HR 5/5). All 3H/14C-ratios of the proteins in the column fractions show that arginylated proteins bind preferentially to the hydrophobic matrices: the fractions eluted first show low 3H/14C-ratios, and after addition of ethylene glycol and especially of Tween 80 the 3H/14C-ratios markedly increase. Furthermore, these arginylated proteins aggregate preferentially after incubation of the cytosol proteins for 2 h at 37 degrees C and are more rapidly degraded by endopeptidases.
Bohley
P
P
Physiologisch-chemisches Institut der Universität Tübingen.
Kopitz
J
J
Adam
G
G
D000818:Animals; D001120:Arginine / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003600:Cytosol / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D011506:Proteins / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D011506:Proteins; D001120:Arginine; D010450:Endopeptidases; D007930:Leucine