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E L Moskvitina

Publications and source records attributed to E L Moskvitina.

7 recordsLinked to original sources
PubMed1991

Polyphosphoinositides as activators of PKC-dependent synapsin I phosphorylation.

The effect of PIP2 and diacylglycerol (products of polyphosphoinositide turnover) on the activation level of phosphorylation of the human brain neurospecific protein SI by PKC from the same source was studied. The apparent activation constant of the phosphorylation process was shown to decrease in the presence of PIP2 from 1.1 micrograms/ml for PI and from 0.8 micrograms/ml to 0.6 microgram/ml for PS; the value of 0.4 microgram/ml in the latter case was detected merely after the addition of DOG into the reaction mixture. Polyphosphoinositides are suggested to play a role in activating PKC-mediated phosphorylation of SI in nerve terminals.

Humans↗
PubMed1991

Ca(2+)-dependent phosphorylation of synapsin I as a possible regulatory mechanism of neurosecretion.

Phosphorylation of homogeneous synapsin I isolated from human brain by Ca2+, phospholipid-dependent protein kinase (protein kinase C) from the same source was studied. The inhibitory effect of calmodulin on this process was demonstrated. The kinetics of activation of synapsin I phosphorylation by acidic phospholipids, phosphatidylserine and phosphatidylinositol, in the absence and presence of phosphatidylinositol-4,5-bisphosphate and diacylglycerol was compared. The proteolytic effect of degradation of the synapsin I molecule phosphorylated by Ca2+, calmodulin-dependent protein kinase II was revealed. No proteolysis of synapsin phosphorylated under similar conditions either by protein kinase C or cAMP-dependent protein kinase was detected. In view of the process specificity, the physiological significance of the observed effect is suggested. The inter-relationship between two ways of neurosecretion regulation is discussed: an earlier known, conventional way, mediated by synapsin I phosphorylation by Ca2+, calmodulin-dependent protein kinase II, and another one, mediated by synapsin I phosphorylation by protein kinase C. The modulating role of polyphosphoinositides in the PK C-dependent way of regulation is considered.

Brain↗
PubMed1989

Synapsin I from human brain. Phosphorylation by Ca2+, phospholipid-dependent protein kinase.

Synapsin I has been isolated from human brain by a rapid and efficient purification technique, and its phosphorylation by human brain Ca2+, phospholipid-dependent protein kinase (protein kinase C) has been studied. The inhibitory effect of calmodulin on this process has been demonstrated. It is also found that non-esterified fatty acids and acidic phospholipids are inhibitory for synapsin I phosphorylation by Ca2+, calmodulin-dependent protein kinase II.

Brain↗
PubMed1983

Essential arginine residues of creatine kinase from beef heart mitochondria.

Creatine kinase from beef heart mitochondria is inactivated by 2,3-butanedione. The kinetics of inactivation of the mitochondrial enzyme is biphasic with a bend at a point corresponding to 50% inactivation. The inactivation rate constants of the first fast and the second slow phases of the reaction differ by one order of magnitude, thus suggesting the existence of two types of arginine residues, i.e. "fast" and "slow" ones, with different reactivities. The inactivation rate constant of the slow phase is very close to that for cytoplasmic creatine kinase. At saturating concentrations MgATP and MgADP afford complete protection of the slow phase of inactivation. It is assumed that the "slow" arginine is involved in the binding of metal-nucleotide substrates in the enzyme active center.

Adenosine Triphosphate↗