Tetrahedral intermediate in a specific alpha-chymotrypsin inhibitor complex detected by laser Raman spectroscopy.

Laser Raman spectroscopy indicates that inhibition of alpha-chymotrypsin by 2-phenylethaneboronic acid occurs in two steps: (i) the formation of a loosely bound complex, in which the boron remains in a trigonal configuration; and (ii) reaction of the boron with a functional group in the catalytic site of the enzyme, resulting in a reversible, stable tetrahedral adduct.