The wide application of biological objects low-temperature storage methods requires studying the temperature influence mechanisms at the molecular level. The effect of +10÷+38°C temperature range on hemoglobin A was studied using the methods of temperature-perturbation spectrophotometry and absorption spectra first derivatives analysis. The ΔE/E dependence on temperature for hemoglobin A solution is of an S-shaped form. On the ΔE/E dependence on temperature for hemoglobin A, breaks are observed: the first in +25÷+27°C temperature range and the second break in +33÷+35°C temperature range. In the experiment performed on myeloma immunoglobulin G, the S-shaped dependence of the temperature-differential spectra intensity on temperature was obtained, which has breaks at +25 and +35°C. The authors attribute this S-shaped dependence to the conformational transition presence in +25÷+35°C temperature range. Apparently, it can be assumed that in the hemoglobin A molecule, conformational changes occur in +25÷+35°C temperature range of +25÷+35°. According to spectrophotometry data, the globin conformational state changes at temperatures around +26÷+30°C. Our studies data indicate the conformational rearrangements presence in the hemoglobin molecule at 25 and 35°C. Our data, presumably indicating a change in the structure of human hemoglobin A at a temperature of about 25°C, are probably confirmed by other studies using dynamic light scattering, incoherent light scattering, IR spectroscopy, studies for intraerythrocyte hemoglobin A of donor blood 5 days of storage on oxyhemoglobin A content, according to which, since a decrease in oxyhemoglobin A content and hemoglobin molecule oxygenation is associated with its conformational state, it is possible that at 25°C a change in the hemoglobin A molecule conformational state begins to appear, which can contribute to a more pronounced decrease in oxyhemoglobin A content. The peculiar properties of HbA, which determine the presence of a special temperature of about 25°C on the various hemoglobin parameters temperature dependences, require further study in comparison in different temperature ranges.
