Imidazolidinone adducts of peptides and hemoglobin

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5220720

San George, R C; Hoberman, H D

Acetaldehyde reacts selectively with the terminal amino groups of the ..cap alpha.. and ..beta.. chains of hemoglobin to form stable adducts, the structures of which, based on /sup 13/C NMR studies, are proposed to be diastereomeric 2-methyl imidazolidin-4-ones. In this scheme, acetaldelhyde forms a reversible Schiff base with the ..cap alpha..-amino groups of the polypeptide chains which cyclize with the amide nitrogen of the first peptide bond to form the stable imidazolidinone adducts. In support of this mechanism, the authors found that in following the reaction of the peptide val-gly-gly with (1,2-/sup 13/C) acetaldehyde, /sup 13/C NMR resonances attributed to a Schiff base (delta = 170 ppm) were observed which slowly disappeared prior to appearance of resonances from a pair of stable adducts (delta = 70 and 71 ppm) believed to be the diastereomeric imidazolidinones. Schiff base formation appeared to limit the overall rate. Tetraglycine reacted in a similar manner but with a resonance from a single stable adduct observed representing the enantiomeric imidazolidinone adducts of this peptide. Peptides with proline in position 2 should be incapable of forming imidazolidinones, and the authors found that ala-pro-gly did in fact fail to form a stable adduct with acetaldehyde. The 2-methyl imidazolidin-4-one adducts of hemoglobin may be useful in determining the contribution of the amino terminal groups to the structure and functional properties of hemoglobins.

• Research Organization: Albert Einstein College of Medicine, Bronx, NY
• OSTI ID: 5220720
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
550600 -- Medicine
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ACETALDEHYDE
ADDUCTS
ALDEHYDES
AZOLES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON 14
CARBON ISOTOPES
CARBOXYLIC ACIDS
EVEN-EVEN NUCLEI
GLOBIN
HEMOGLOBIN
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
IMIDAZOLES
IMINES
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MOLECULAR STRUCTURE
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PEPTIDES
PIGMENTS
PORPHYRINS
PROTEINS
RADIOISOTOPES
RESONANCE
SCHIFF BASES
SPECTRA
YEARS LIVING RADIOISOTOPES