Novel haloperoxidase substrates. Alkynes and cyclopropanes

Area of Science:

• Biochemistry
• Enzymology
• Organic Chemistry

Background:

• Haloperoxidase enzymes catalyze the halogenation of organic molecules.
• Understanding the substrate scope and reaction mechanisms of haloperoxidases is crucial for synthetic biology and drug discovery.

Purpose of the Study:

• To identify new substrate classes for haloperoxidase-mediated halogenation.
• To elucidate the reaction mechanism and propose a general scheme for these novel transformations.

Main Methods:

• Enzymatic reactions using haloperoxidase with alkyne and cyclopropane substrates.
• Analysis of reaction products to identify halogenated compounds.
• Comparison of product selectivities to propose a reaction mechanism.

Main Results:

• Discovery of two new substrate classes: alkynes and cyclopropanes.
• Enzymatic halogenation of alkynes yields alpha-halogenated ketones.
• Enzymatic halogenation of cyclopropanes yields alpha, gamma-halohydrins.

Conclusions:

• A novel reaction mechanism involving hypohalous acid intermediate is proposed, differing from previous models.
• These findings expand the known reactivity of haloperoxidases.
• The biosynthetic implications of these novel reactions are discussed.