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D Njus

Publications and source records attributed to D Njus.

42 records · Page 3Linked to original sources
PubMed1976

Adenosine triphosphate-evoked catecholamine release in chromatin granules. Osmotic lysis as a consequence of proton translocation.

Chromaffin granules suspended in C1-containing media release catecholamine and protein when ATP is added. This phenomenon is inhibited in hyperosmotic media and in the presence of uncouplers of oxidative phosphorylation. Release requires a permeant anion in the medium, but is independent of the cation. The release process appears to be driven by an inwardly directed proton-translocating adenosine triphosphatase. The resulting proton-anion influx causes osmotic lysis of the chromaffin granules.

Adenosine Triphosphate↗
PubMed1976

Dinoflagellate bioluminescence: a comparative study of invitro components.

In vitro bioluminescence components of the dinoflagellates Gonyaulax polyedra, G. tamarensis, Dissodinium lunual, and Pyrocystis noctiluca were studied. The luciferases and luciferins of the four species cross-react in all combinations. All of these species possess high-molecular weight luciferases (200,000-400,000 daltons) with similar pH activity profiles. The active single chains of luciferases from the Gonyaulax species have a MW of 130,000 while those from P. noctiluca and D. lunula have a MW of 60,000. Extractable luciferase activity varies with time of day in the two Gonyaulax species, but not in the other two. A luciferin binding protein (LBP) can easily be extracted from the two Gonyaulax species (MW approximately 120,000 daltons), but none could be detected in extracts of either D. lunula or P. noctiluca. Scintillons are extractable from all four species, but they vary in density and the degree to which activity can be increased by added luciferin. Although the biochemistry of bioluminescence in these dinoflagellates is generally similar, the observations that D. lunula and P. noctiluca apparently lack LBP and have luciferases with low MW single chains require further clarification.

Animals↗
PubMed1976

Membranes and molecules in circadian systems.

A membrane clock model involving ions and ion transport is compatible with the limit cycle concept, biochemical studies, and the idea of phase shifting by ion gating. It provides an explanation for temperature compensation, and, by assuming that oscillating ion concentrations regulate the many different biochemical and physiological rhythms, it explains how diverse systems can be controlled by a single oscillatory mechanism. How ions control ion transport and which membranes are involved in the clock are two questions we have begun to explore.

Animals↗