When we eat protein foods the protein is digested in the gut by enzymes into single amino acids. (howmuchprotein.com)
The cells lining our digestive tract absorb single amino acids or small chains of two or three amino acids, which are broken down in the intestinal wall cells. (fitnessandpower.com)
Brunger and his colleagues found that altering the toxin at the binding site by single amino acid changes (obtained from the high resolution crystal structure) drastically reduced its toxicity. (hhmi.org)