Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Covalent binding of benzo(a)pyrene-diol-epoxide to histone H2A in rat liver nuclei: target site specificity

Conference · · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)
OSTI ID:5207905

The authors have recently found that 7r,8t-dihydroxy-9t,10t-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BPDE-I), a strong carcinogen, binds selectively to histone H2A-2 variant in rat liver nuclei, using a high performance liquid chromatography (HPLC) system which can separate H4, H2B, 3 different fractions of H2A variants and 3 different H3 variants in an hour. Here the authors examined the binding site of BPDE-I to the H2A-2 variant. The H2A-2 variants were purified from the acid extracted core histones of rat liver nuclei treated with (/sup 3/H)-BPDE-I by the HPLC system with a semi-preparative Aquapore RP-300 column. HPLC analysis of cyanogen bromide treated-H2A-2, which has one methionine residue, showed that the binding site is located in C-terminal half of H2A-2. In addition, digestions with V8-protease, trypsin and different types of carboxypeptides suggested that there are some target amino acid residues for BPDE-I in the V8-proteolytic C-terminal octapeptide which contains 2 histadine and 3 lysine residues. Currently identification of the target amino acid is proceeding, using amino acid-BPDE adducts prepared in vitro.

Research Organization:
Univ. of Texas System Cancer Center, Smithville
OSTI ID:
5207905
Report Number(s):
CONF-8606151-
Journal Information:
Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:6; ISSN FEPRA
Country of Publication:
United States
Language:
English