Use of 1-anilino-8-naphthalene-sulfonate as a probe of gastric vesicle transport

Abstract

The interaction of 1-anilino-8-naphthalene-sulfonate (ANS) with vesicles derived from hog fundic mucosa was studied in the presence of valinomycin and with the addition of ATP. Evidence was found for two classes of sites, those rapidly accessible to ANS with aK _D of 7.5 μm and those slowly accessible, but rapidly accessed in the presence of valinomycin with aK _D of 2.5 μm. ATP transiently increases the quantum yield of the latter ANS binding sites only in the presence of valinomycin, but does not alter the number ofK _D of those sites. The time course of this increase correlates with H⁺ uptake and Rb⁺ extrusion by those vesicles and H⁺ carriers such as tetrachlorsalicylanilide or nigericin abolish the ATP response. With ATP addition in the presence of SC¹⁴N and valinomycin there is transient uptake of SCN⁻. It is concluded that ANS is acting as a probe of a structural change dependent on a potential and H⁺ gradient.