Fernando Zambrano

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Several partial reactions of the Na(+)-K+ pump enzyme were studied in a microsomal fraction derived from the gill of carp (Cyprinus carpio Linneo). We tested the effect of three toxins [(i) microcystin-LR, (ii) microcystin-LR-like toxin component isolated from Microcystis aeruginosa culture and (iii) okadaic acid] on the phosphorylation, ouabain binding and(More)
A method is reported for the isolation of a highly purified fraction of urinary bladder membranes containing hexagonal plaques. The method uses zonal centrifugation as the final step of fractionation. The purified fraction was characterized by its electron microscopic morphology, by its enzymatic profile, by quantitative and qualitative analysis of lipids(More)
Golgi apparatus isolated from both rat liver and rat kidney have been characterized with respect to their neutral and phospholipid content and their phosphopipid composition and compared with mitochondria, rough endoplasmic reticulum and plasma membranes. In addition, the distribution of sulfatide in the subcellular fractions of rat kidney was determinich(More)
A microsomal fraction rich in (Na+ + K+)-ATPase has been isolated from the outer medulla of pig kidney. (Mg2+ + K+)-activated ouabain-sensitive phosphatase activity was studied in this preparation treated with arylsulphatase, an enzyme that specifically hydrolyzes ceramide galactose-3-sulphate. The activity of phosphatase was inactivated in proportion to(More)
The sulphatide content of vesicular membrane fraction from rabbit mucosal gastric microsomes was analyzed. This vesicular membrane fraction, in addition to a high sulphatide content, was enriched in an ouabain-insensitive (H+ + K+)-ATPase, a (Mg+2 + K+)-activated phosphatase, and a H+ pumping activity. The enzyme system involved in the process of acid(More)
A procedure has been developed for the isolation of morphologically recognizable, largely intact, Golgi apparatus from rat kidneys. The fraction contains both uridine diphosphogalactose: IVacetylglucosamine galactosyltransferase and 3’-phosphoadenosine 5’-phosphosulfate: cerebroside sulfotransferase activities enriched 50to 80-fold over the original(More)
The experiments we are going to report are concerned with the following questions" (a) Does the cell membrane actively transport sodium when it is supplied with ATP as the only substrate? (b) Is it possible to correlate active transport with (Na q-K)-activated ATPase-catalyzed reaction taking place in vitro in fragments of squid axon membranes? We have(More)