The enzyme-substrate complex in the active site
Lysozyme enzyme complex with its substrate
The folding of the peptide chain of the lysozyme, dominated by helical structures, creates a kind of invagination in which the substrate of the enzyme is lodged, represented here by the backbone of this small molecule. The close relationship between the enzyme and its substrate lowers ...
Credits: RCSB PDB (rcsb.org) of 3GXR (Helland et al. 2009 Cell.Mol.Life Sci. 66: 2585-2598)
Direct evidence of the formation of ES complexes was provided much later by physicochemical techniques, either indirectly by examining the variation of a parameter - for example spectroscopic of the enzyme as a function of the substrate (change in absorption wavelength d 'an amino acid of the enzyme for example) - either directly, and this is now the general method, by examining the interaction of the enzyme and the substrate on three-dimensional models obtained by X-ray diffraction of enzyme-substrate co-crystals, by NMR, etc.