Chemical synthesis and structure elucidation of bovine kappa-casein (1-44).

The caseins (alphas1, alphas2, beta, and kappa) are phosphoproteins present in bovine milk that have been studied for over a century and whose structures remain obscure. Here we describe the chemical synthesis and structure elucidation of the N-terminal segment (1-44) of bovine kappa-casein, the protein which maintains the micellar structure of the caseins. kappa-Casein (1-44) was synthesised by highly optimised Boc solid-phase peptide chemistry and characterised by mass spectrometry.