[The photodestruction of hemoglobin]. / O fotodestruktsii gemoglobina.

It was shown that hemoglobin photodestruction occurs in the process of light absorption by protein globin, as well as by its hem. Quantum yields of photoreactions decreased with the increase of irradiation wave length. We observed two mechanisms of photodestruction: dependent and independent on the existence of the dissolved oxygen in solution. Hemoglobin photodestruction due to hem absorption did not exist in the absence of dissolved oxygen.

[Effect of ceruloplasmin conformation on its activity: significance for clinical analysis]. / O vliianii konformatsii tseruloplazmina na ego aktivnost': znachenie dlia klinicheskogo analiza.

Conformational properties of ceruloplasmin were studied immediately in blood serum of healthy volunteers, patients with tuberculosis, with pulmonary cancer, with pneumonia and with Wilson-Konovalov disease. The glycoprotein conformation was found to depend on the volunteer physiological state and/or available pathology. The ceruloplasmin conformation and status of its copper-containing sites of the I type affected the enzyme oxidase properties and hence routine colorimetric procedures require some corrections for estimation of ceruloplasmin concentration and activity in blood serum.

[Features of photochemical properties of hemoglobin under native conditions]. / Osobennosti fotokhimicheskikh svoistv gemoglobina v nativnykh usloviiakh.

The photochemistry of human hemoglobin (Hb) in the blood and blood serum (lambda = 254-578 nm) was studied, using spectrophotometric methods. The Hb photochemistry is a complex set of photoreactions leading to successive photoconversions of Hb forms: from oxy- to met- to deoxy- and, finally, to carboxy-form. The photodestruction of Hb and the photoreactions involving other serum proteins were found to occur simultaneously. In the blood Hb photomodifications are localized directly in erythrocytes. The conditions necessary for the photo--induced rupture of erythrocyte membranes and the subsequent release of Hb into the blood plasma, were determined. Although the general characteristics of Hb photochemistry are the same for model systems and for native conditions, there are some distinctions in the effectiveness of the photoconversion. It seems likely that the observed effects are due to the antioxidant properties of the serum. These properties may be the cause of the inhibition of blood photohemolysis upon irradiation (lambda greater than or equal to 300 nm).

[Photoconversion of hemoglobin forms in buffer solutions under the effect of ultraviolet and visible radiation]. / Fotoprevrashcheniia form gemoglobina v bufernykh rastvorakh pod deistviem ul'trafioletovogo i vidimogo izluchenii.

Using spectrophotometric methods, the photochemical behaviour of hemoglobin in buffer solutions irradiated at 254-578 nm was studied. It was found that the hemoglobin photochemical activity is manifested in a cascade of photoreactions involving at least four protein forms and soluble oxygen. Hemoglobin photoconversions were observed both upon light absorptions by the globin and the heme. The efficiency of photoreactions decreased with an increase in the wavelength of the irradiating light. The values of quantum yields of the above photoreactions were determined.

[A novel form of copper-containing centers in human ceruloplasmin]. / Novaia forma med'soderzhashchikh tsentrov v tseruloplazmine cheloveka.

Using spectral methods (EPR, spectrophotometry), it was demonstrated that type II Cu2(+)-centers (so-called non-blue centers) are represented in human ceruloplasmin by two (but not one) stable forms which differ in their EPR spectra and absorption properties. Differential spectra were recorded, and the difference in the extinction coefficients of these forms was determined. Both forms were detected by the EPR method in blood sera from healthy and diseased individuals. The relative amount of these forms depends on the origin of the disease. This finding opens new perspectives in the diagnostic application of the EPR method. Spectrophotometric evidence of the ferroxidase activity of serum ceruloplasmin towards hemoglobin was obtained; other serum components were also shown to be involved in this process.