Monoclonal antibodies to the apical chloride channel in Necturus gallbladder inhibit the chloride conductance.

AUTOR(ES)

Finn, A L

RESUMO

Monoclonal antibodies raised by injecting Necturus gallbladder cells into mice were tested for their ability to inhibit the apical chloride conductance induced by elevation of cellular cAMP. Five of these monoclonal antibodies bound to the apical cells, as shown by indirect immunofluorescence microscopy, and inhibited the chloride conductance; one antibody that bound only to subepithelial smooth muscle, by indirect immunofluorescence microscopy, showed no inhibition of chloride transport. The channel or a closely related molecule is present in the membrane whether or not the pathway is open, since, in addition to inhibiting the conductance of the open channel, the antibody also bound to the membrane in the resting state and prevented subsequent opening of the channel. The antibody was shown to recognize, by ELISA, epitopes from the Necturus gallbladder and small intestine. Finally, by Western blot analysis of Necturus gallbladder homogenates, the antibody was shown to recognize two protein bands of Mr 219,000 and Mr 69,000. This antibody should permit isolation and characterization of this important ion channel.

Documentos Relacionados

• A chloride conductance activated by adenosine 3',5'-cyclic monophosphate in the apical membrane of Necturus enterocytes.
• Halothane shortens acetylcholine receptor channel kinetics without affecting conductance.
• Chloride channel and chloride conductance regulator domains of CFTR, the cystic fibrosis transmembrane conductance regulator
• Fatty acids inhibit apical membrane chloride channels in airway epithelia.
• Vitamin C controls the cystic fibrosis transmembrane conductance regulator chloride channel