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Biomedical subjects

E Zoch

Publications and source records attributed to E Zoch.

12 recordsLinked to original sources
PubMed1990

Neuraminidase in juvenile calf thymus: determination and characterization by a continuous fluorometric assay procedure.

A continuous fluorometric neuraminidase assay has been developed. Within the pH range optimal for neuraminidases (from 3 to 6) the fluorescence intensity of 4-methylumbelliferone exceeds that of the glycoside 4-methylumbelliferyl-alpha-D-N-acetylneuraminic acid about 50 times (at lambda Ex = 335 nm and lambda Em = 445 nm), allowing the precise, simple and time-saving continuous fluorometric registration of enzymatically released 4-methylumbelliferone. In juvenile calf thymus a neuraminidase consisting of two components differing in pH optima and resistence to freezing and to detergents could be found. A beta-galactosidase activity in juvenile calf thymus could be proved by the same assay procedure using the synthetic substrate 4-methylumbelliferyl-beta-D-galactopyranoside.

Animals↗
PubMed1984

[Continuous measurement of the catalytic activity of adenosine deaminase using the pH stat method].

The enzymatic deamination of adenosine to inosine produces ammonia, which causes a pH-increase of the reaction mixture. The pH-stat method is based on the continuous addition of protons to keep the pH at a constant value. The theoretical principles are discussed. The quantitative limits of the assay and the effect of changing the pH were investigated. A correction factor was derived and calculated for the pH range 6.4 to 8.5. This sensitive method allows the continuous recording of the adenosine deaminase activity in strongly coloured or turbid biological samples.

Adenosine Deaminase↗
PubMed1977

[Subcellular distribution of adenosine-, adenosine-5-monophosphate- and cytidine-5-monophosphate desaminase activity in the humna placenta and amnion tissue].

With the method of pH-Stat the adenosinedeaminase-, adenosine-5'-monophosphate deaminase-, cytidine-5'-monophosphate deaminase activities are determined in the nucleus-, mitochondrial-, microsomalfractions and in the cytoplasmatic fractions of the human termplacental and amniotic tissues. The desaminase activities were higher in the amniotic fractions. The possible importance of the adenosinedesaminase and adenosine-5'-monophosphate desaminase for the fetal-placental blood circulation is discussed.

AMP Deaminase↗
PubMedDate not supplied

Purification and characterization of calcium-activated neutral proteinase from calf thymus.

A calcium-activated neutral proteinase (CANP) was prepared from the soluble fraction of calf thymus and purified to electrophoretical homogeneity. The purified proteinase was shown to consist of two subunits, each of 80 kDa, in contrast to rabbit skeletal muscle calpain which was shown to consist of 80 kDa and 30 kDa subunits. The calcium requirement for 50% activation was 0.55 mM, indicating that this enzyme belongs to the low calcium sensitive type CANP, named mCANP or Calpain II. Optimal conditions of enzyme activity towards 0.8% casein as substrate are pH 7.5, a calcium concentration of 1.5 mM, the presence of an SH-reducing agent and an incubation temperature of 30 degrees C. The enzyme is inhibited by Zn2+, p-chloromercuribenzoate and N-ethylmaleimide.

Animals↗