@entity17463 reacts with the @entity413 carrier of @entity1 erythrocytes at a rate which is greatly altered in the presence of competitive inhibitors of @entity413 transport. Inhibitors bound to the carrier on the outer surface of the membrane, either at the substrate site ( @entity7969 ) or at the external inhibition site ( @entity16802 and @entity21146 ), more than double the reaction rate. Inhibitors bound at the internal inhibition site (cytochalasin B and @entity2671 ), protect the system against @entity17464 . After treatment with @entity17464 , the maximum transport rate falls to less than one-third, and the properties of the binding sites are modified in unexpected ways. The affinity of externally bound inhibitors rises: @entity16802 is bound up to seven times more strongly and @entity21146 and maltose twice as strongly. The affinity of cytochalasin B, bound at the internal inhibition site, falls to half while that of @entity2671 is little changed. The affinity of external @entity413 falls slightly. @entity2671 prevents both the fall in transport activity and the increase in @entity16802 affinity produced by @entity17464 . An inhibitor of anion transport has no effect on the reaction. The observations support the following conclusions: @entity17464 produces its effects on the @entity413 transport system by reacting with the carrier on the outer surface of the membrane. The carrier assumes distinct inward-facing and outward-facing conformations, and @entity17464 reacts with only the outward-facing form. The @entity1432 group with which @entity17464 is presumed to react is not present in either the substrate site or the internal or external inhibitor site.(ABSTRACT TRUNCATED AT 250 WORDS)

Reaction of the @entity413 carrier of erythrocytes with XXXX : evidence for inward-facing and outward-facing carrier conformations.

@entity1 :: ('9606', 'Species') :: ['human'] @entity7969 :: ('MESH:D008320', 'Chemical') :: ['maltose'] @entity17464 :: ('CHEBI:16094', 'Chemical') :: ['tetrathionate', 'Tetrathionate'] @entity16802 :: ('MESH:D010693', 'Chemical') :: ['phloretin'] @entity1432 :: ('CHEBI:29256', 'Chemical') :: ['thiol'] @entity17463 :: ('MESH:D013776', 'Chemical') :: ['Sodium tetrathionate'] @entity2671 :: ('MESH:D000735', 'Chemical') :: ['androstenedione', 'Androstenedione'] @entity413 :: ('MESH:D005947', 'Chemical') :: ['glucose'] @entity21146 :: ('MESH:D010695', 'Chemical') :: ['phlorizin']
@entity17463 :: (MESH:D013776,Chemical) :: ['sodium tetrathionate']
