The measurement of small angle neutron scattering in the solution of α-crystalline (concentration 8 mg/ml) with variation contrasts in four buffers has been carried out. The first buffer contained 100 % Н2О, the second - 77 % Н2О – 23 % D2O, the third - 32 % Н2О – 68 % D2O, the fourth - 10 % Н2О – 90 % D2O. The preliminary analysis of observations was done. Radius of gyration and maximum size and volume of α-crystalline in buffers with different D2O concentration were obtained. The values of these structural parameters are practically independent on D2O concentration in buffer and are similar to the parameters obtained by the method of small angle X-ray scattering. The independence of gyration radius on D2O concentration in buffer is evidence of homogeneous density of α-crystalline macromolecule. This is a new experimental fact.
The investigation of temperature realignment of α-crystalline macromolecule by the small angle neutron scattering method has been carried out as well. The measurements have been done with the buffer containing of 90 % D2O at temperatures 20, 50, 60, 65, 75, 85 and 95 оС during the heating and cooling stages and with the buffer containing of 100 % Н2О at 20 оС before and after heating to 95 оC. As a result of the experiments for the first time were obtained the structural data about α-crystalline by the small angle scattering method in wide range of high temperature (the measurements were carried out directly at high temperatures). These data will be used for analysis of α-crystalline realignment at high temperatures. This is important for understanding of mechanism of shaperon similar α-crystalline activity depending on temperature prehistory of this protein.