Effect of the peptide bronchogen (Ala-Asp-Glu-Leu) on DNA thermostability.
Thermodynamic parameters of DNA melting in the presence of a peptide bronchogen in various concentrations were estimated on a differential scanning microcalorimeter. Bronchogen was shown to serve as a DNA-stabilizing agent. Bronchogen increased the melting temperature of DNA from calf thymus and mouse liver by 3.1°C in a narrow range of r (molar ratio of bronchogen/DNA b.p., 0.01-0.055). A further increase in r was not accompanied by changes in the melting temperature. The complex melting enthalpy (ΔH(melt)) remained unchanged in this range of r (0.01-1.0). ΔH(melt) for DNA from the thymus and mouse liver was 11.4 and 12.7 cal/g, respectively. Our results indicate that bronchogen is not an adenine-thymine-specific or guanine-cytosine-specific ligand. The type of binding is considered as strong and occasional. The binding occurs with both strands of DNA (mainly with nitrogen bases).
E. Andronikashvili Institute of Physics, Tbilisi, Georgia.
J R
JR
Monaselidze
V Kh
VKh
Khavinson
M Z
MZ
Gorgoshidze
D G
DG
Khachidze
E M
EM
Lomidze
T A
TA
Jokhadze
T A
TA
Lezhava
D000818:Animals; D002152:Calorimetry, Differential Scanning; D002417:Cattle; D051379:Mice; D009691:Nucleic Acid Denaturation / Q000187:drug effects*; D010455:Peptides / Q000494:pharmacology*; D044366:Transition Temperature
D010455:Peptides