Strictosidine synthase

According to structural studies of strictosidine synthase from Rauvolfia serpentina, tryptamine is located at the bottom of the pocket, where Glu 309 forms a hydrogen bond with the substrate's primary amine group.

[3] Strictosidine synthase facilitates 3-α(S)-strictosidine formation by acting as a scaffold to increase local concentrations of tryptamine, secologanin, and acid catalysts.

As stated in the introduction, strictosidine synthase catalyzes the biological Pictet–Spengler reaction of tryptamine and secologanin to stereoselectively form 3-alpha(S)-strictosidine, the universal precursor for monoterpenoid indole alkaloid compounds.

The encoding gene is rapidly down-regulated by auxin, an essential promoter in cell division, leading to lower levels of alkaloid accumulation.

[8] Several studies of the Catharanthus roseus strictosidine synthase indicate that the enzyme plays a regulatory role in sustaining high rates of alkaloid biosynthesis.

[9] No additional cofactors are needed for strictosidine synthase to achieve optimal activity, although early studies of the enzyme derived from Apocynaceae plants identified ''p''-chloromercuribenzoate as a potent inhibitor.

[11] Also, binding with various secologanin analogs with the same stereoselectivity as that of 3-alpha(S)-strictosidine can be achieved through the mutation of aspartate-177 to alanine, permitting the synthesis of a wider range of possible alkaloid compounds for further drug discovery investigations.