[ATPase activity of myosin and its intermediate states recorded by a dual-frequency fluorescence technic].
Explore the source record for details and available documents.
Adenosine Triphosphate↗
Biomedical subjects
V L Zima
Publications and source records attributed to V L Zima.
[Fluorescent studies on conformational states of human plasminogen. I. pH effect].
Conformational transitions of human plasminogen were studied by the fluorescent analysis according to the shift of the fluorescence spectrum maximum and the fluorescence dynamic quenching method. At pH 9.0-6.0 plasminogen has a stable native conformation, with a decrease of pH from 6.0 down to 5.3 the fluorescence spectrum maximum moves towards the short-wave region and with the subsequent lowering of pH--to the long-wave region. A share of the available protein tryptophanyls to quenchers KI and acrylamide in the neutral and weak-acid media is determined. The analysis of the data obtained permits considering that the plasminogen molecule at pH 5,3 is of a more compact structure than at pH 7.0; at pH 2.0 it loosens preserving the compact packing.
Humans↗
[Fibrinogen and fibrin monomer conformation changes dependent of pH magnitude].
Conformational states of fibrinogen and fibrin monomer were studied by methods of differential and solvent-perturbation spectrophotometry and ultraviolet fluorescence at about neutral pH (6.5) and in the region of lower pH, 3.2 to 4.0. To prevent repolymerization of fibrin monomer at pH 6.5, urea was added in a non-denaturing concentration of 1.7 M. In the acid region specified, the immediate environment of tyrosine and tryptophan residues was found to be more polar and the accessibility to perturbants higher than at pH 6.5. Much more drastic changes of the same type occurred at pH less than 3 when denaturation of the protein takes place. The conformation of fibrinogen altered progressively upon lowering pH from 4.0 to 3.2. This acidity increase, practically, did not influence the conformation of fibrin monomer. Thus the tolerance of the latter to the appearance of the new positively changed groups seems to be comparably high. The bulk of the conformational changes subsequent upon neutralization of an acid fibrin monomer solution proceeds at a higher rate than the activation transition, i.e. the acquirement of a state of polymerization readiness by fibrin monomer molecules.
Animals↗
[Structure and aggregation of histones. I. Influence of the ionic composition of the medium on the structure and effectiveness of the intermolecular relationships of histone F2a (H2A+H4)].
The investigation of fluorescence and light-scattering change of histone F2a, ribonuclease, tyrosine, N-acetyltirosinamide, methyl ether tyrosine by the concentration increasing of NaCl, MgCl2, Na2SO4 in the surrounding medium was carried out. In the case of used salts the changes of tertiary structure and histones aggregations depend on the anion type, which is presented in the environment. The tertiary structure of histones formed in the presence of salt is stabilized by weak (hydrophobic and hydrogenic) interactions.
Chemical Phenomena↗
[Protein motors: structure and generation of mechanical force].
Recent data about the structural and functional features of protein motors (myosin, dynein, kinesin) are presented. The mechanism by which the chemical energy of ATP is transduced into mechanical work is discussed.
Animals↗