The presence of a heat-stable cytosolic factor in rat submandibular gland which activates Na+,K+-ATPase.
A low molecular weight substance is present in the soluble fraction of the rat submandibular gland which activates Na+,K+-ATPase. Varying amounts of cytosolic protein from rat submandibular gland were added to a heavy microsomal preparation of the same tissue. A dose-dependent activation of the Na+,K+-ATPase was observed, with a peak activation of approximately 82% occurring when 9.0 micrograms/mL of cytosolic protein was included in the assay. The activating factor is heat stable and soluble following heat treatment. The factor elutes at a molecular mass of 600 daltons as determined by molecular sieve column chromatography. Ultraviolet-visible scanning of the elute material results in an absorbance at 210 nm, which is characteristic of a low molecular weight peptide.
D000818:Animals; D003600:Cytosol / Q000378:metabolism; D004355:Drug Stability; D004789:Enzyme Activation; D006358:Hot Temperature; D007700:Kinetics; D008297:Male; D011506:Proteins / Q000302:isolation & purification / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D012995:Solubility; D013363:Submandibular Gland / Q000201:enzymology*
D011506:Proteins; D000254:Sodium-Potassium-Exchanging ATPase