Enables the transfer of L-arabinose from one side of a membrane to the other. Arabinose occurs free, for example in the heartwood of many conifers and in the combined states, in both furanose and pyranose forms, as a constituent of various plant hemicelluloses, bacterial polysaccharides, etc.
L-arabinose/beta-D-thiogalactopyranoside:hydrogen antiporter activity