Table 2. Nitrogen to Protein Conversion Factors (N-factors), Protein Contents and Purities, Molar Weights, Numbers of Peptide Bonds Per Gram of Protein (h_tot), Numbers of Amino Acids (AAs), Molar Extinction Coefficients at 214 nm (ε₂₁₄), Numbers of Cleavage Sites (CS), Theoretical Maximum Degrees of Hydrolysis (DH_max,theo) of the Three Trypsins (Bovine, Porcine, and Human) and Two Proteins (α-Lactalbumin and β-Casein) and Numbers of Unique Peptides in Each Hydrolysate.

proteina	UniProt codeb	N-factorb [grams of protein per gram of N]	protein content [w/w]	purityc [%]	molar weightd [Da]	htote [mmol/g]	CSb	AAb	DHmax,theo [%]	ε214 [M–1·cm–1]	α-LAf peptides	β-casf peptides
α-LA	P00711	6.25	93%	90	14 186	8.6	13	123	10.7	300 461
β-cas	P02666	6.39	90%	90	23 983f	8.7	15	209	7.2	424 047
BT	P00760	5.97	80%	100	23 305	—	—	223	—	—	23	34
PT	P00761	5.84	86%	100	23 475	—	—	223	—	—	30	36
HT	P07478	5.98	77%	100	24 041	—	—	224	—	—	30	40

^aα-LA, α-lactalbumin; β-cas, β-casein; BT, bovine trypsin; PT, porcine trypsin; HT, human trypsin.

^bFrom UniProt (http://www.uniprot.org).

^cThe protein purity is defined as the percentage of the total UV₂₈₀ peak area that is the UV₂₈₀ peak area of the target protein, determined by RP-UPLC.

^dThe molar weight was calculated with five phosphoserines on the β-cas molecule, as shown in RP-UPLC-MS.

^eh_tot is the number of millimoles of peptide bonds per gram of protein calculated using the amino acid sequence and the molecular weight of the protein as reported in Uniprot.

^fα-LA and β-cas peptides stand for the unique peptides identified in the hydrolysates of α-LA and β-cas, respectively.