PMID- 19369590
OWN - NLM
STAT- MEDLINE
DCOM- 20090803
LR  - 20211020
IS  - 0032-0889 (Print)
IS  - 1532-2548 (Electronic)
IS  - 0032-0889 (Linking)
VI  - 150
IP  - 2
DP  - 2009 Jun
TI  - Galactonolactone dehydrogenase requires a redox-sensitive thiol for optimal 
      production of vitamin C.
PG  - 596-605
LID - 10.1104/pp.109.136929 [doi]
AB  - The mitochondrial flavoenzyme l-galactono-gamma-lactone dehydrogenase (GALDH) 
      catalyzes the ultimate step of vitamin C biosynthesis in plants. We found that 
      recombinant GALDH from Arabidopsis (Arabidopsis thaliana) is inactivated by 
      hydrogen peroxide due to selective oxidation of cysteine (Cys)-340, located in 
      the cap domain. Electrospray ionization mass spectrometry revealed that the 
      partial reversible oxidative modification of Cys-340 involves the sequential 
      formation of sulfenic, sulfinic, and sulfonic acid states. S-Glutathionylation of 
      the sulfenic acid switches off GALDH activity and protects the enzyme against 
      oxidative damage in vitro. C340A and C340S GALDH variants are insensitive toward 
      thiol oxidation, but exhibit a poor affinity for l-galactono-1,4-lactone. Cys-340 
      is buried beneath the protein surface and its estimated pK(a) of 6.5 suggests the 
      involvement of the thiolate anion in substrate recognition. The indispensability 
      of a redox-sensitive thiol provides a rationale why GALDH was designed as a 
      dehydrogenase and not, like related aldonolactone oxidoreductases, as an oxidase.
FAU - Leferink, Nicole G H
AU  - Leferink NG
AD  - Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The 
      Netherlands.
FAU - van Duijn, Esther
AU  - van Duijn E
FAU - Barendregt, Arjan
AU  - Barendregt A
FAU - Heck, Albert J R
AU  - Heck AJ
FAU - van Berkel, Willem J H
AU  - van Berkel WJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20090415
PL  - United States
TA  - Plant Physiol
JT  - Plant physiology
JID - 0401224
RN  - 0 (Spin Labels)
RN  - 0 (Sulfhydryl Compounds)
RN  - EC 1.3.- (Oxidoreductases Acting on CH-CH Group Donors)
RN  - EC 1.3.2.3 (galactonolactone dehydrogenase)
RN  - GAN16C9B8O (Glutathione)
RN  - K848JZ4886 (Cysteine)
RN  - PQ6CK8PD0R (Ascorbic Acid)
SB  - IM
MH  - Amino Acid Sequence
MH  - Arabidopsis/*enzymology
MH  - Ascorbic Acid/*biosynthesis
MH  - Catalytic Domain
MH  - Cysteine/metabolism
MH  - Electron Spin Resonance Spectroscopy
MH  - Enzyme Activation
MH  - Glutathione/metabolism
MH  - Kinetics
MH  - Molecular Sequence Data
MH  - Oxidation-Reduction
MH  - Oxidative Stress
MH  - Oxidoreductases Acting on CH-CH Group Donors/chemistry/*metabolism
MH  - Protein Folding
MH  - Sequence Homology, Amino Acid
MH  - Spectrometry, Mass, Electrospray Ionization
MH  - Spin Labels
MH  - Sulfhydryl Compounds/*metabolism
MH  - Time Factors
PMC - PMC2689977
EDAT- 2009/04/17 09:00
MHDA- 2009/08/04 09:00
PMCR- 2010/06/01
CRDT- 2009/04/17 09:00
PHST- 2009/04/17 09:00 [entrez]
PHST- 2009/04/17 09:00 [pubmed]
PHST- 2009/08/04 09:00 [medline]
PHST- 2010/06/01 00:00 [pmc-release]
AID - pp.109.136929 [pii]
AID - 136929 [pii]
AID - 10.1104/pp.109.136929 [doi]
PST - ppublish
SO  - Plant Physiol. 2009 Jun;150(2):596-605. doi: 10.1104/pp.109.136929. Epub 2009 Apr 
      15.