acetylenzyme

Acetylenzyme is a term sometimes used to refer to enzymes that act on acetylenes (alkynes), enabling activation and transformation of the carbon–carbon triple bond. It is not a standard or widely used name in contemporary enzymology; more precise terms describe individual enzymes, such as acetylene hydratase, which hydrates acetylene to acetaldehyde, and other alkyne-functionalizing enzymes.

Typical reactions envisioned for acetylenzymes include hydration, hydroamination, hydrogenation, and oxidation of alkynes, yielding products such as acetaldehyde, amines, alkanes, or carboxylic acids, depending on the enzyme and reaction conditions. These reactions would expand the range of biocatalytic transformations available under mild, aqueous conditions.

Mechanistic features of acetylenzymes often involve metal cofactors and redox partners. Tungsten- or molybdenum-containing cofactors, in combination with iron-sulfur clusters, are known in related acetylene-activating enzymes and support challenging bond activations. While specifics vary among enzymes, the general theme is the activation of a relatively inert triple bond by a metalloenzyme to enable downstream chemistry.

Occurrence and significance: The best-characterized example is acetylene hydratase, found in certain anaerobic bacteria that metabolize acetylene. The broader concept of acetylenzymes remains largely limited to this and related alkyne-activating activities described in enzymology literature, rather than a defined, standalone enzyme family.

Applications and outlook: If broadly realized, acetylenzymes could enable sustainable biocatalysis for selective alkyne functionalization, synthesis of aldehydes or amines, and potentially detoxification of acetylene-rich environments. Key challenges include expanding substrate scope, stability, and compatibility with industrial processes.