[Study of the Mg2+-ATPase reaction of myosin using the NMR-31P method. Detection of adenylate kinase activity in a purified myosin subfragment I]. / Primenenie metoda IaMR-31P dlia izucheniia Mg2+-ATPaznoi reaktsii miozina. Ovnaruzhenie adenilatkinaznoi aktivnosti v ochishchennom preparate subfragemnta l miozina.

Isolated myosin heads (HMM-S1) were concentrated by ultrafiltration in an "Amicon" cell to a concentration of 120 mg/ml. Incubation of HMM-S1 with ATP in the presence of Mg2+ produced an AMP peak in the spectrum of NMR-31P whose size was increasing linearly with the reaction time. It was demonstrated that after heating of the sample the appearance of AMP in the incubation mixture was due to the presence of a small amount of adenylate kinase (or myokinase) in the purified preparation of HMM-S1.

[Determination of the secondary prothrombin structure under different degrees of citraconylation by means of ring dichroism]. / Opredelenie metodom krugovogo dikhroizma vtorichnoi struktury protrombina pri raznoi stepeni tsitrakonilirovaniia

A process of spontaneous activation of bovine prothrombin under acylation of cytacone anhydride is studied by means of ring dichroism and disc electrophoresis in sodium dodecylsulphate. Ring dichroism data have shown that native prothrombin contains 14% of alpha-helical structures, 36% of beta-structures and 50% of random coil. Cytraconylation results in a fragmentation of native prothrombin chain and is accompanies by the decrease of alpha-helical regions in the fragments formed. Poly-L-lysine, modified by citracone anydride, does not form alpha-helical regions.