Mutarotase inhibitors

With the establishment of the permease hypothesis, however, it was apparent that the mere formation of a complex with the mutarotase protein may be the necessary interaction in transport (15). The subsequent mutarotation could be considered to be a coincidental consequence of the complex formation. To support this idea, it was found that 1-deoxy glucose and a-methyl glucoside are excellent competitive inhibitors of the enzyme (16,61). Keston also showed that a number of cataractogenic sugars were inhibitors of lens mutarotase (62). It has since been shown that in all cases where a sugar is a substrate for the mammalian intestinal transport system it is also a competitive inhibitor of mutarotase. 

Figure 5. Competitive inhibitors of bovine kidney mutarotase...

However, if these limitations are remembered, it can be instructive to compare the patterns of interaction which have been variously reported for substrates and inhibitors of mutarotase, with similar patterns for the kidney and intestinal sugar transport processes. In Table XIII the reported specificities for mammalian intestine are compared. In cases where comparative data are available, all sugars which are actively transported or which are passively transported but share the same carrier as glucose also interact with the active center of mutarotase. Particularly interesting is the observation that L-fucose, the most potent sugar inhibi-... 

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