Molecular Classification
Casein, Phosphoprotein
Other Names
A2 milk protein, A2 beta casein, A2 β-casein

Beta-casein A2 variant Overview

The A2 protein most commonly refers to the A2 variant of beta-casein, a major milk protein. The primary difference between A1 and A2 beta-caseins is at amino acid position 67—proline in A2 versus histidine in A1. Some studies suggest that consuming only the A2 variant may reduce digestive discomfort compared to regular milk containing both variants.

Mechanism of Action

Biological Functions

Nutrient delivery
Micelle formation
Source of amino acids
Calcium binding
Phosphate binding

Disease Associations

No disease associations available

Safety Considerations

  • Potential digestive discomfort in sensitive individuals with A1 beta-casein intolerance