Conformational Changes in DNA and Protein Biomolecules in Pathogenesis of Ischemic Stroke.

Conformational changes in DNA and protein biomolecules were studied in ischemic stroke (IS) cases varying severity by Raman spectroscopy. The conformational structure of hematoporphyrin was found to change in IS patients, leading to a higher (I₁₃₅₅/I₁₅₅₀)/(I₁₃₇₅/I₁₅₈₀) ratio (hemoglobin affinity of for ligands) and an increase in I₁₃₇₅/I₁₁₇₂ (a change in pyrrole conformation). Changes in genomic DNA spectra were observed at frequencies caused by stretching vibrations of primary amines (3400 cm^-1), secondary amines and hydroxyls involved in hydrogen bonding (3100 cm^-1), and CH₂ groups of sugar phosphates (2900 cm^-1) and vibrations of vibrational bonds between nitrogenous bases and sugars (1400 cm^-1). The significant changes observed in genomic DNA and hemoglobin spectra were assumed to indicate conformational rearrangements of the molecules in IS. Severe IS was associated with maximum changes in DNA and hemoglobin spectra.