[Experience in the use of synchrotron radiation for the x-ray study of biopolymers]. / Opyt ispol'zovaniia sinkhrotronnogo izlucheniia dlia rentgenograficheskogo issledovaniia biopolimerov

The results of methodical work, carried out on the sources of synchrotron radiation (SR) with the aim of using SR as a powerful source of X-rays for studying biopolymer structure, are presented. The questions of monochromatization are considered. The technique designed for photoregistration of diffraction patterns within the wide range of scattering angles is described. X-ray diffraction patterns of feather ceratin, collagen and striated muscle are obtained with exposure periods ten times less than those in the case of X-ray tubes. The high resolution of diffraction lines, the absence of parasitic phone and the presence of reflections within the wide range of scattering angles are characteristic of these patterns.

[Use of linear proportional chambers for small-angle synchrotron radiation scattering in solutions of biopolymers]. / Ispol'zovanie odnokoordinatnykh proportsional'nykh kamer v metode malouglovogo rasseianiia sinkhrotropnogo izlucheniia na rastvorakh biopolimerov

The results of applying linear position sensitive proportional counters to diffuse small-angle synchrotron radiation scattering to biopolymer solutions are presented. Synchrotron radiation of the VEPP-3 storage ring (Institute of Nuclear Physics, Novosibirsk) was used. On the basis of small-angle scattering curve obtained from protein pepsinogen it has been shown that the exposure is about 100 times less than with conventional X-ray technique.

[High time resolution x-ray study of the dynamics of a single muscle contraction]. / Rentgenograficheskoe issledovanie dinamiki odinochnogo myshechnogo sokrashcheniia s vysokim vremennym razresheniem.

A method of the diffraction cinema which enables to study the time-course of structural changes during twitch contraction is described. The method is based on using synchrotron radiation, position-sensitive counter and small-angle focusing X-ray camera. Only 0.1 s is required to record a good muscle X-ray diagram: meridional diagram contains all layer-lines beginning with the 429 A; the equatorial diagram contains 5 reflections including very weak alpha-reflection. The method allows to record 64 sequent diffraction patterns with different duration (1--2000 ms). The experiment is handled by a computer. Some tens of the films of isometric twitch contraction with time resolution of 3--20 ms have been obtained. During isometric contraction considerable changes in the intensity of both meridional and equatorial reflections were found. The changes were interpreted as indicating movement of cross-bridges toward the thin filaments. During the latent phase there are no visible changes in the intensity of the reflections; the result indicates that during this phase there are no structural changes in position and configuration of cross-bridges.