Interaction of the maltose‐binding protein with spheroplasts of Escherichia coli

The maltose-binding protein (MBP) of E. coli is an essential element in maltose transport as well as in maltose chemotaxis. It is released by osmotic shock, i.e. it is a periplasmic protein. It binds maltose reversibly with a K sub(D) of 1 mu M, and the alpha 1-4-linked higher maltodextrins. Fluorescence changes of MBP, upon binding with maltose, have been observed; they reflect ligand induced conformational changes. Both maltose transport and chemotaxis require MBP, the malE) gene product. Maltose transport requires four additional genes, coregulated with malE , in the maltose regulon. Maltose chemotaxis requires many additional genes, different from those implicated in transport. Some of the gene products necessary for transport or chemotaxis, are located in the inner membrane of E. coli . In the present study, the authors report a specific binding of the MBP to spheroplasts of E. coli , in the presence of maltose.