The other variety I keep on hand is rice protein; should have a very different amino acid profile to the whey protein. (holdthetoast.com)
The whey provides a quick hit of aminos to boost protein synthesis, while the casein provides a slower source of aminos to slow down protein breakdown, plus you get slightly different amino acid profiles. (nupush.net)
The human body is perfectly capable of forming complete proteins from different foods with different amino acid profiles, provided the combination provides all Essential Amino Acids. (mnprime.com)