Some physicochemical characteristics of equine abortion virus nucleic acid

Abstract

Physicochemical studies have been carried out on the deoxyribonucleic acid (DNA) of equine abortion virus. The buoyant density was 1.716 g/ml and the melting temperature was 51.4°C, both equivalent to a guanine plus cytosine content of 57 mole per cent. The DNA, extracted and purified with a minimum of degradation, gave sedimentation coefficients of 49–52 S under the conditions employed by Rubenstein et al. (1961). The estimated molecular weight based on the sedimentation relationship reported by these authors ranged from 83.6 to 93.8 million. Molecular weights for these same preparations determined by band-width measurements were not in agreement until the DNA had been chromatographed on a methylated-albumin column. A sample of DNA treated in this manner had a molecular weight of 93.8 × 10 6 determined from its S value and 92 × 10 6 from band-width measurements. The molecular weight for this same material based on the length of the DNA molecule, determined by electron microscopy, was 92.2 × 10 6 daltons.