Carcinogenesis, Vol 18, 1035-1038, Copyright © 1997 by Oxford University Press
Q Li, J Laval and DB Ludlum
Transfection of the Escherichia coli fpg gene into Chinese hamster ovary
cells has been reported to enhance survival after exposure to aziridine
(C.Cussac and F.Laval, 1996, Nucleic Acids Res., 24, 1742- 1746). This
result suggests that Fpg protein protects cells from toxicity by removing
ring-opened N-7 guanine adducts from DNA, and raises the possibility that
Fpg protein would offer protection from other agents that alkylate the N-7
position of guanine. Since the major adduct formed by sulfur mustard in DNA
is 7-hydroxyethyl- thioethylguanine (HETEG), we have investigated the
action of Fpg protein on the ring-opened form of this adduct (ro-HETEG). A
substrate containing ro-HETEG was prepared by alkaline treatment of DNA
modified by [14C]sulfur mustard. Fpg protein purified from an
over-producing strain of E. coli released ro-HETEG from this substrate in
an enzyme- and time-dependent manner, and at a rate that is similar to that
at which it releases ring-opened 7-methylguanine. Thus, Fpg protein acts
efficiently on ro-HETEG, and may offer some protection against the toxic
action of sulfur mustard.
ARTICLES
Fpg protein releases a ring-opened N-7 guanine adduct from DNA that has been modified by sulfur mustard
Department of Pharmacology and Molecular Toxicology, University of Massachusetts Medical School, Worcester 01655-0126, USA.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
S. A. Smith and B. P. Engelward In vivo repair of methylation damage in Aag 3-methyladenine DNA glycosylase null mouse cells Nucleic Acids Res., September 1, 2000; 28(17): 3294 - 3300. [Abstract] [Full Text] [PDF] |
||||
