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Iu V Chumachenko

Publications and source records attributed to Iu V Chumachenko.

14 recordsLinked to original sources
PubMedDate not supplied

[High-voltage electrophoresis and its application in combination with other methods for protein structure studies].

The method of high-voltage paper electrophoresis may be applied not only for peptide separation, but also in modifications and combinations with other methods, so, by means of aminoethylation and maleylation it is possible to broaden or narrow the range of trypsin action. This, in its turn, makes it possible to isolate preparatively lysin- and arginine-containing peptides, oxidation with performic acid enables the thyol-containing fragments to be isolated and application of carboxypeptidase A-C-terminal peptide of protein. When studying the primary structure of proteins the method has already found its widest application but with an increase in the number of methods of protein specific modification its potentiabilities will be even wider.

Carboxypeptidases↗
PubMedDate not supplied

[Comparative characteristics of catalase from the fungus Penicillium vitale, which is synthesized under different nutritional conditions].

A comparative study of properties (absorption spectra, thermostability, pH optimum, polyacrylamide gel electrophoresis, DEAE-cellulose separation) and structure (amino acid composition, finger-prints, carbohydrate composition) was performed for P. vitale catalase synthesized under different medium conditions. In all cases the results were similar. The only difference occured in the amount of synthesized proteins. A conclusion is drawn that under different nourishing conditions of the fungus the properties and structure of the catalase are unchanged, but the regulatory mechanisms of catalase and glucosooxidate synthesis undergo changes.

Amino Acids↗
PubMedDate not supplied

[Structuro-functional characteristics of aldolase from rabbit muscles in diabetes].

The structural peculiarities of rabbit muscle aldolase accompanying enhancement of the aldolase activity in diabetes are described from the data of tryptophan phosphorescence at the room temperature and fluorescence polarization. It is shown that the pathology-concomitant conformational changes occur in both the hydrophobic part and NAD-binding site of the enzyme. The character of the structural changes in the hydrophobic part of the protein in diabetes and an increase in the enzymic activity are similar to that observed in normal aldolase after its interaction with NADH and are believed to be associated with the enhancement of the rigidity in the Trp-147 environment.

Animals↗
PubMedDate not supplied

[Interaction of aldolase A with lecithin liposomes].

The aldolase A binding to the lecithin liposomes (Kd = 2.4 +/- 0.1 X 10(-3) M) has been shown by the fluorescence and tryptophan phosphorescence at the room temperature. The interaction is accompanied by an increase in the phospholipid bilayer microviscosity, and some conformational changes in the hydrophobic part of the enzyme, pronouncing themselves in Trp-147 environment rigidity, decrease. The observation of membrane viscosity vs. incubation time revealed practically instant enzyme-membrane interaction and no gradual incorporation. The accessibility of the NAD-binding domain of aldolase for NADH in the liposome presence remains unaltered.

Fructose-Bisphosphate Aldolase↗
PubMedDate not supplied

[Stabilizing effect of oligomerization on aldolase protomers in rabbit muscles].

It is shown by the fluorimetric analysis that with the 1,2 M MgCl2-induced dissociation of rabbit muscle aldolase the tertiary structure of the resulted protomers (subunits) remains practically unchanged. Significant changes in the protomeric enzyme are provoked by subsequent addition of urea up to the concentration of 2,3 M, and are, evidently, manifested in a significant decrease in regularity of the hydrophobic part of aldolase and in possible transition of its Trp-147 into more polar environment. This transition is reflected in the longwave shift of the protein fluorescence maximum (lambda max) by 13 nm (from 320 to 333 nm). But the joint action of MgCl2 and urea does not lead to complete unfolding of the resulted protomeric enzyme. More deep structural alterations in the subunits occur on acidic dissociation, and lambda max shift in this case reaches 342 nm. Structural changes caused by MgCl2 and urea are concomitant with the increase of fluorescence quenchibility with NADH. Here a short-wave lambda max shift, being usually observed in native aldolase fluorescence quenching, is not registered. This mean that the photoselection of protein fluorophores does not occur. The results thus obtained produce an evidence that oligomerization endows aldolase protomers with enhanced stability.

Animals↗
PubMedDate not supplied

[Comparative study of the structural characteristics of aldolase in rabbit muscles in normal states and in alloxan diabetes].

It is shown that the activity of aldolase synthesized in rabbit muscles under diabetes is higher than that at normal state. This fact is probably a result of some structural alterations in NAD-binding site with Trp-291 and -311 in it which overlaps a considerable part of C-terminal region of the protein. The hydrophobic part of the enzyme containing Trp-147 under diabetes seems to remain unaltered. This consideration is based on the longwave shift in aldolase fluorescence lambda max (from 320 to 324 nm) under this pathology, suggesting a transition of Trp-291 and -311 into more polar environment and is confirmed by the disappearance of the difference in lambda max in the NADH presence. The NADH-originated shift in lambda max position for the both proteins ended at the same wave-length at 314 nm. The position of lambda max at 324 nm resulting from possible structural modification of NAD-binding site under diabetes correlates with an increase in the Stern-Volmer quenching constant value (from 4359 to 7500 M-1 for aldolase under normal and diabetic states, respectively). These quenching data evidence in favour of the suggestion on the existence of two classes of tryptophanyls in the aldolase molecule.

Animals↗
PubMedDate not supplied

[Effect of NADH on the catalytic function and reactivity of thiols from rabbit muscle aldolase].

NADH has a corresponding binding site in aldolase, and can activate the reaction of the aldole cleavage of the substrate (fructose-1,6-bisphosphate). Unlike the considerable protection by the substrate, the similar effect of NADH on the sulphydryl enzyme groups is less pronounced, and may be attributed to single cysteine residue. The functionally related and spatially separated binding sites for NADH and substrate are suggested.

Animals↗
PubMedDate not supplied

[Simple technic for multiple small sample lyophilization].

This simple and easily reproducible technique does not pretend to be new in principle but is still very convenient for drying numerous samples. The advantage of the technique is based on preliminary sample freezing just before dessication. The tubes must be sealed with needle punctured cellophane to avoid the samples squeezing out by ice-entraped air bubbles. This approach is especially convenient for protein structure investigations when it is necessary to dry and accumulate peptides from the maps on high-voltage electrophoresis and chromatography. In a 1.5-litre dessicator some 20 ml of sample can be dried out without reloading.

Freeze Drying↗