# Protometabolic functions of pyridoxal: A link between early amino acid synthesis and enzyme evolution

## TL;DR

This paper explores how pyridoxal could have played a key role in early amino acid synthesis and enzyme evolution, supporting the idea that metabolism came before life as we know it.

## Contribution

The study reveals pyridoxal's protometabolic role in nitrogen incorporation into amino acids under pre-enzyme conditions.

## Key findings

- Pyridoxal converts to pyridoxamine under early Earth-like conditions.
- These conditions enabled nitrogen incorporation into amino acids before enzymes existed.
- Pyridoxal's role supports the 'metabolism first' theory of biological evolution.

## Abstract

In the framework of studies on protometabolism, Schlikker et al. characterized the conversion of pyridoxal to pyridoxamine under conditions mimicking the ones likely existing at the origin of metabolism. These conditions triggered nitrogen incorporation into amino acids in solution before the origins of enzymes. The suggested role for pyridoxal highlights its pivotal function in the transition from inorganic ammonia‐dependent amino acid synthesis to organic reactions in aqueous solution and supports the “metabolism first” theory for biological evolution. Insights from the early evolution of natural enzymes can inspire the development of novel biocatalysts for biotechnological applications based on the catalytic versatility of pyridoxal.

Schlikker et al. characterized the conversion of pyridoxal to pyridoxamine under conditions mimicking the ones likely existing at the origin of metabolism. These conditions triggered nitrogen incorporation into amino acids in solution before the origins of enzymes. The suggested role for pyridoxal highlights its pivotal function in the transition from inorganic ammonia‐dependent amino acid synthesis to organic reactions in aqueous solution and supports the “metabolism first” theory for biological evolution. Insights from the early evolution of natural enzymes can inspire the development of novel biocatalysts for biotechnological applications based on the catalytic versatility of pyridoxal.