Lack of immunological cross reactivity between the transport enzymes (Na+ + K+)-ATPase and (K+ + H+)-ATPase

Abstract

Goat antisera against (Na+ + K+)-ATPase and its isolated subunits and against (K+ + H+)-ATPase have been prepared in order to test for immune cross-reactivity between the two enzymes, whose catalytic subunits show great chemical similarity. None of the (Na+ + K+)-ATPase antisera cross-reacted with (K+ + H+)-ATPase or inhibited its enzyme activity. The same was true for the (K+ + H+)-ATPase antiserum with regard to (Na+ + K+)-ATPase and its subunits and its enzyme activity. So notwithstanding the chemical similarity of their subunits, there is no immunological cross-reactivity between these two plasma membrane ATPases.

The H+/K+‐ATPase (proton) pump is expressed in human laryngeal submucosal glands

“…The positive control in the present study was immunohistochemically stained gastric tissue revealing positive parietal cells along the typical distribution, with a negative control of no staining in other neighboring cell types of the stomach. Possible cross‐reaction of the H + /K + ‐ATPase antibody with the Na + /K + ‐ATPase was not shown in the present study and has also been addressed by other authors 8–12 . Most important, skeletal muscle in the larynx (which has a high concentration of Na + /K + ‐ATPase) showed no staining and was confirmed as a negative control.…”

Proton Pump (H+/K+‐ATPase) Expression in Human Laryngeal Seromucinous Glands

“…13 Possible cross-reaction of the H ϩ /K ϩ -ATPase antibody with the Na ϩ /K ϩ -ATPase was not shown in our present or prior 8 studies and has also been addressed by others. 14 Esophageal epithelial cells have also been shown to possess ion exchange pumps. Inspired by prior work demonstrating a Na ϩ /H ϩ antiport in rabbit esophageal cells, 15 Tobey et al 16 used cultured esophageal epithelial cells incubated with fluorescent dye, and pulsed with acidification to demonstrate recovery of the intracellular pH through H ϩ extrusion.…”

The MRP4/ABCC4 Gene Encodes a Novel Apical Organic Anion Transporter in Human Kidney Proximal Tubules

“…The eluted, affinity-purified, anti-rat Mrp4 (pAb rM4-p1; 2 mg/ml) and anti-human Mrp4 (pAb hM4-p3; 3 mg/ml) antibodies were used in immunohistochemical and immunoblot analyses (see below). Monoclonal antibody (mAb) M 2 III-6 is directed against rat Mrp2 and cross-reacts with human MRP2 (23), and pAb G34 is directed against the rat Na ϩ /K ϩ -ATPase (24). A pAb directed against the rat sodium/phosphate type IIa cotransporter was kindly provided by Dr. J. Biber (Institute of Physiology, University of Zurich, Zurich, Switzerland).…”