Human gastric juice contains mainly aspartate proteinases: pepsin A and pepsin C. Both pepsins are produced by gastric mucosa as inactive pepsinogens and they are activated to the corresponding pepsins in the acidic environment of the gastric lumen.
The levels of pepsinogens in serum reflect the morphological and functional status of gastric mucosa. A subject of this thesis is a part of a long-term investigation that focuses on the elaboration of methods for separation gastric aspartate proteainases that would be suitable for diagnostic purposes.
The preparation of new type ligands was a concrete subject of PhD. thesis that after their immobilization they can enable the separation of aspartate proteinases. Four heptapeptides containing D-leucinyl residue were synthetized (Val-D-Leu-Pro-Phe-Phe-Val-D-Leu, Val-D-Leu-Pro-Tyr-Phe-Val-D-Leu, Val-D-Leu-Pro-Tyr-Tyr-Val-D-Leu and Val-D-Leu-Pro-Phe-Tyr-Val-D-Leu.