June 18, 2021, 10:54:57 PM
Forum Rules: Read This Before Posting


Topic: benzoquinone as a possible covalent modifier of an enzyme  (Read 213 times)

0 Members and 1 Guest are viewing this topic.

Offline Babcock_Hall

  • Chemist
  • Sr. Member
  • *
  • Posts: 4740
  • Mole Snacks: +282/-21
benzoquinone as a possible covalent modifier of an enzyme
« on: May 05, 2021, 05:43:09 PM »
https://pubs.acs.org/doi/10.1021/tx300417z
"Substituent Effects on the Reactivity of Benzoquinone Derivatives with Thiols"
We study an enzyme that has an essential, nucleophilic cysteine residue.  In two organisms this enzyme is reversibly inhibited by 1,4-benzoquinone.  We were studying the same enzyme in a third organism.  My student performed a pre-incubation experiment with our enzyme on this compound.  These assays are typically used to detect covalent bond formation with concomitant inactivation of the enzyme.  They can be used whether or not the enzyme and inactivator have affinity for each other.  It appears that some inactivation is taking place.  What little I was able to turn up quickly makes the possibility of inactivation seem plausible, but I don't have much experience with how reactive 1,4-benzoquinones are.  Thoughts?
« Last Edit: May 05, 2021, 06:00:36 PM by Babcock_Hall »

Offline Babcock_Hall

  • Chemist
  • Sr. Member
  • *
  • Posts: 4740
  • Mole Snacks: +282/-21
Re: benzoquinone as a possible covalent modifier of an enzyme
« Reply #1 on: May 05, 2021, 10:46:15 PM »
PMID: 31248982  PMCID: PMC6699853  DOI: 10.1074/jbc.RA119.008666
I did another quick search and found that benzoquinone also covalently modifies the nucleophilic cysteine residue in a protein tyrosine phosphatase enzyme.

Sponsored Links