What is the Origin of D-Amino Acid?

The D- and L- designations originate from the Latin dextro (right) and laevo (left), referring to the direction in which the molecules rotate plane-polarized light. The biochemical distinction highlights the fundamental stereoselectivity of biological systems, which primarily utilize the L-configuration. The deliberate use of D-Amino Acids in synthetic peptides arose from the need to improve the metabolic stability of these therapeutic agents.

What is the Mechanism of D-Amino Acid?

The substitution of a native L-Amino Acid with its D-Amino Acid counterpart at a critical position within a peptide chain creates a structural barrier to degradation by endogenous proteases and peptidases. This modification significantly enhances the peptide's resistance to enzymatic cleavage, thus prolonging its biological half-life and increasing its systemic bioavailability. Furthermore, the altered spatial configuration can sometimes confer beneficial changes in receptor binding affinity or selectivity.

D-Amino Acid

Meaning

A D-Amino Acid is the stereoisomer, or non-superimposable mirror image, of the L-Amino Acid form, which constitutes the vast majority of proteins found in the human body. These two forms exist due to the chirality of the alpha-carbon atom, and while L-Amino Acids are the canonical building blocks of mammalian peptides, D-Amino Acids are naturally found in some microbial cell walls and select neuropeptides. Their incorporation into therapeutic peptides is a key strategy in pharmaceutical design to modify drug properties.