Lysosomal prenylcysteine lyase is a FAD-dependent thioether oxidase.

Published

Journal Article

Prenylated proteins contain either a 15-carbon farnesyl or a 20-carbon geranylgeranyl isoprenoid covalently attached via a thioether bond to a cysteine residue at or near their C terminus. As prenylated proteins comprise up to 2% of the total protein in eukaryotic cells, and the thioether bond is a stable modification, their degradation raises a metabolic challenge to cells. A lysosomal enzyme termed prenylcysteine lyase has been identified that cleaves prenylcysteines to cysteine and an unidentified isoprenoid product. Here we show that the isoprenoid product of prenylcysteine lyase is the C-1 aldehyde of the isoprenoid moiety (farnesal in the case of C-15). The enzyme requires molecular oxygen as a cosubstrate and utilizes a noncovalently bound flavin cofactor in an NAD(P)H-independent manner. Additionally, a stoichiometric amount of hydrogen peroxide is produced during the reaction. These surprising findings indicate that prenylcysteine lyase utilizes a novel oxidative mechanism to cleave thioether bonds and provide insight into the unique role this enzyme plays in the cellular metabolism of prenylcysteines.

Full Text

Duke Authors

Cited Authors

  • Tschantz, WR; Digits, JA; Pyun, HJ; Coates, RM; Casey, PJ

Published Date

  • January 26, 2001

Published In

Volume / Issue

  • 276 / 4

Start / End Page

  • 2321 - 2324

PubMed ID

  • 11078725

Pubmed Central ID

  • 11078725

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.C000616200

Language

  • eng

Conference Location

  • United States