title: Homocysteine effect on protein degradation rates.
abstract: OBJECTIVE
  To show the effect of homocysteine (Hcy) on the degradation rates of proteins.
  
  
  METHODS
  Degradation rates of short-lived proteins in neutrophils were measured in in vivo human model of elevated plasma Hcy and lower vitamin status and in animal model of Hcy added in vitro to rat neutrophils.
  
  
  RESULTS
  In the human study, we found significant coefficients of correlation between plasma total homocysteine (tHcy) and the degradation rates of 21 protein fractions. In the animal model, Hcy significantly increased degradation rates of 57 protein fractions.
  
  
  CONCLUSIONS
  The increase in protein degradation rates, induced by Hcy, may provide a clue to our understanding of the mechanism of Hcy detrimental effects. Hcy may amplify the specific effect of cellular solutes on protein conformation, thereby monitor protein degradation rates to control enzyme activity. Consequently, the cell may lose its ability to maintain an efficient control of some crucial metabolic pathways, possibly leading to atherogenesis.
authors.affiliation: Institute of Biochemistry, Food Science and Nutrition, Faculty of Agriculture, Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
authors.forename: Felicia
authors.initials: F
authors.lastname: Stern
authors.forename: Yitshal N
authors.initials: YN
authors.lastname: Berner
authors.forename: Zeev
authors.initials: Z
authors.lastname: Polyak
authors.forename: Margarita
authors.initials: M
authors.lastname: Komarnitsky
authors.forename: Ben-Ami
authors.initials: BA
authors.lastname: Sela
authors.forename: Micha
authors.initials: M
authors.lastname: Hopp
authors.forename: Yosef
authors.initials: Y
authors.lastname: Dror
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000378:metabolism; D006710:Homocysteine / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D006801:Humans; D008297:Male; D009504:Neutrophils / Q000737:chemistry / Q000378:metabolism; D011506:Proteins / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000378:metabolism; D025101:Vitamin B 6 / Q000008:administration & dosage / Q000378:metabolism
chemical_list: D011506:Proteins; D006710:Homocysteine; D025101:Vitamin B 6; D005492:Folic Acid; D014805:Vitamin B 12