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Iu B Magarshak

Publications and source records attributed to Iu B Magarshak.

18 recordsLinked to original sources
PubMedDate not supplied

[Graph method of analyzing the stationary kinetics of polyenzyme systems].

Methods based on the graphical representation of relations between metabolites concentrations were worked out for the description and analysis of the steady-state kinetics of the multienzyme systems. The properties of graphics characterizing various steady-state regimens were investigated. Relations relevant to the analysis of regulatory phenomena were derived for the concentration of non-adjacent metabolites. Rules are presented for the kinetical description of multienzyme systems posessing external inputs and outputs. Certain branchings occuring in multienzyme systems were considered. The developed methods allow generalization concerning multisubstrate multiproduct reactions as well as systems containing regulatory enzymes with non-michaelian kinetics. It is suggested that the generalized methods may be helpful for the analysis of the metabolic regulation.

Catalysis↗
PubMedDate not supplied

[Description of the ratios between metabolite concentrations in a polyenzyme system].

It was demonstrated that the relations between substrate and product concentrations for a reaction catalyzed by michaelian enzyme incorporated in a multienzyme system can be graphically represented by a diverging set of straight lines intersecting in one point, the flux velocity being treated as a parameter. A competitive inhibitor shifts the intersection point along the line of equilibrium state. The relations between the concentrations of more than two reagents are represented by a set of equivelocity surfaces. The relations between substrate and product concentrations for a kinetically cooperative reaction conforming to the graphical representation by the second--order curves were analyzed. The stability criterion was obtained for a multienzyme system with the first enzyme allosterically regulated by products of subsequent reactions.

Allosteric Regulation↗
PubMedDate not supplied

[Application of a graphic method for analyzing the kinetics of multienzyme reactions].

A new graphic method is proposed to solve kinetic equations for polyenzymic reactions. Each graph apex is corresponded by the transmitting function deduced from kinetic equations by means of Laplas transformation. Application of this procedure allows to simplify the solution of kinetic equations and its analysis. The procedure suggested makes it possible to use the methods of automatic control when solving theoretical problems of enzymology.

Enzymes↗
PubMedDate not supplied

[Dynamic superhelicity in vivo and in vitro].

As it was shown in studies of J. Dubochet using the recently developed method of three-dimensional cryo-microscopy, the interaction of RNA polymerase with plasmid gives rise to a superhelical structure. In this process, two RNA polymerase molecules are located at opposite ends of the plasmid at the tops of the superhelix. The dynamic features of this process are considered, which may be only one of many similar processes, in which energy dissipation during the directed movement of DNA is reduced to a minimum. It is assumed that, upon screwing of two double helices into each other, a three- dimensional mechanical transmission is formed, owing to the spatial features of the double helices comprising the superhelix, which further facilitates this twisting process.

DNA, Recombinant↗
PubMedDate not supplied

[Analysis of the dynamics of transitions in Leptomonas collosoma spliced leader RNA and a possible role of gaps upon splicing].

In [1], the existence of two competing secondary structures at the 5'-end of Leptomonas collosoma spliced leader RNA was shown. On going from one steady-state secondary structure to the other, and vice versa, RNA passes through several states in which the chain gets tied up into nodes. If the transitions are reversible, the nodes are figurative both in the forth and back directions although the secondary structures that arise in this process are quite different, and the forth and back routs do not coincide. It is assumed that under certain conditions, the chain can get tied into the next node of series 5(2), which most likely will not get untied. This node is tightened around GG nucleotides. In this case, the migration of the gap is possible, as a result of which the chain can break. Independent experiments indicate that the RNA chain breaks just at this site upon splicing. Based on these results, a possible role of nodes in the enzymatic activity is discussed.

Animals↗