title: Ethionine causes the formation of NG-monoethylarginine in nuclear proteins from regenerating rat liver.
abstract: In a previous report, administration of [3H]ethylethionine to partially hepatectomized rats was shown to ethylate two classes of proteins extracted from rat liver nuclei in 0.25 N HCl. Upon acid hydrolysis of the proteins, ethyl derivatives of both lysine and arginine were found. The arginine derivative which represented the major ethylated product is identified in this report as NG-monoethylarginine by the use of alkali hydrolysis. Administration of methionine along with the ethionine partially inhibited the ethylation. This suggests that the ethylation may proceed in a similar manner to normal protein methylation by which the methylases utilize S-adenosylmethionine as the ethyl donor. Using in vitro assays for both protein-lysine and protein-arginine methyltransferase it was found that only the protein-arginine methyltransferase could use radiolabeled S-adenosylmethionine as a substrate. The major product formed in this assay was identified as NG-monoethylarginine.
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D005001:Ethionine / Q000494:pharmacology*; D008115:Liver Regeneration; D008297:Male; D009698:Nucleoproteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity
chemical_list: D009698:Nucleoproteins; C036911:N(G)-monoethylarginine; D001120:Arginine; D005001:Ethionine