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V Kinzel

Publications and source records attributed to V Kinzel.

At least 109 records · Page 6Linked to original sources
PubMed1980

Generation of pyrophosphate from extracellular ATP at the surface of HeLa cells.

On incubation of intact HeLa cells with micromolar concentrations of [gamma 32 P]ATP under physiological conditions, the generation of inorganic pyrophophate in the supernatant has been observed. The reaction depends on incubation time and cell number employed; the enzymatic activity is not shed into the supernatant. Isotope dilution data support that the responsible enzyme(s) is located at the cell surface.

Adenosine Triphosphatases↗
PubMed1979

Isolation of the catalytic subunits of cyclic AMP-dependent protein kinases from different mammalian tissues on the basis of charge differences of their subunits.

Both, the experimental data and a literature survey presented reveal common charge differences in the subunit composition of cAMP-dependent protein kinases from a variety of mammalian tissues. In general, the holoenzymes (type I and II) focus at pH 4.5-5.5, the cAMP-binding regulatory subunit below pH 4, whereas catalytic subunits are found at pH 6.7-9.1. For the purification of the catalytic subunits, the anionic holoenzymes of a variety of rat and rabbit organs as well as mouse and human-derived tissue culture cells were adsorbed to DEAE-cellulose. The catalytic subunit from the particular isoenzyme were selectively eluted at an appropriate ionic strength depending on the isoenzyme elution pattern by small amounts of cAMP. Extraction of tissues with Triton X-100 increased enzyme yield. Improved elution of the enzyme was accomplished by 8-(4-aminobutyl)amino-cAMP instead of cyclic AMP. Carboxymethyl-cellulose chromatography leads to both, concentration and, if necessary, to further purification of the enzyme.

Animals↗
PubMed1976

Lens culinaris lectin immobilized on sepharose: binding and sugar-specific release of intact tissue culture cells.

Lens culinaris lectin (LCL) covalently linked to 2B Sepharose binds tissue culture cells to the matrix. This is prevented by hapten sugars specific for LCL. Unlike other immobilized lectins, lens culinaris lectin allows the removal of bound cells from the matrix on addition of the specific sugars in a concentration-dependent manner. Binding and release occur under physiological conditions. Released cells continue to grow.

Cell Membrane↗
PubMed1976

Phospho-accepting proteins in bovine sera.

Phospho-accepting proteins in bovine sera have been detected by the use of immobilized protein kinase from rat muscle and (gamma32P)-ATP in an in vitro system. A partial biochemical characterization points to the generation of typical phosphoproteins. Differences in the phosphorylation pattern between fetal serum and calf serum as demonstrated by electrophoresis in the presence of dodecylsulfate are described.

Adenosine Triphosphate↗
PubMed1975

Solid-state protein kinase. A tool for post-synthetically modifying and radioactively labeling proteins in vitro.

The capacity of partially purified rat muscle protein kinase coupled to cyanogen-bromide-activated Sepharose 4B to (radio-)phosphorylate proteins in vitro was evaluated using histones from calf thymus and rat liver and certain proteins as substrates. Data are presented which point to a low substrate specificity of this enzyme. It is demonstrated that even within a short time period histones are efficiently phosphorylated without the introduction of contaminating (phospho-)proteins. Therebye phosphoserine residues are formed. The phosphorylation reaction usually performed at 30 degrees C is shown to function quite efficiently also at 4 degrees C. It proceeds even at 30 degrees C for several hours at pH values close to the physiological range without the release of proteins from the solid matrix. The phosphorus transfer can be largely increased with the use of high ATP concentrations. The stability of the substrates is sufficient to suggest a wide applicability of this solid-state protein kinase in the phosphorylation of proteins either for labeling or as a tool to modify proteins post-synthetically under gentle conditions. The solid enzyme seems to be suitable for radioactively labeling proteins of more complex biological structures, such as membrane surfaces.

Animals↗