Protein Hydrolysates and Amino Acid Requirements
When protein hydrolysates are used as an amino acid source, the amount of free amino acids and short peptides is important as they can be transported directly over the cell membrane of several types of cells. In the cytosol these peptides can be further digested to free amino acids by peptidases.
Proteins and peptides can also be absorbed through endocytosis after which they are digested to free amino acids in the lysosomes and released into the cytosol.
There are indications that amino acids absorbed as peptides influence cell metabolism in a different way than those absorbed as free amino acids. Several growth studies were performed successfully with different cell lines including hybridoma cell lines, CHO and BHK cells in cell culture media, supplemented with vegetable protein hydrolysates of the HyPep™ series as the sole amino acid source.
These studies suggest that for optimal performance the media must contain an amount of free amino acids in the range of 10-40%. The exact amount depends on the type of the protein hydrolysate and therefore the hydrolysates in the HyPep™ series have been optimized and tailored for specific cell line requirements.
