alpha-chymotrypsin has been researched along with endomorphin-1* in 2 studies
2 other study(ies) available for alpha-chymotrypsin and endomorphin-1
| Article | Year |
|---|---|
Stability against enzymatic hydrolysis of endomorphin-1 analogues containing beta-proline.
The enantiomer of endomorphin-1 (Tyr-Pro-Trp-PheNH2) and the analogues containing (S)- or (R)-beta-proline have been synthesized, and their affinities towards mu-opioid receptors have been measured. As expected, the incubations of the different peptides with some commercially available enzymes showed that the presence of D-residues gave strong resistance towards digestion. The presence of beta-proline alone is sufficient to confer good resistance against the hydrolysis of the biologically strategic Pro-Trp bond. Topics: Animals; Carboxypeptidases; CD13 Antigens; Chymotrypsin; Hydrolysis; Oligopeptides; Proline; Rats; Receptors, Opioid, mu; Stereoisomerism; Tryptophan | 2003 |
Endomorphin-1 analogues containing beta-proline are mu-opioid receptor agonists and display enhanced enzymatic hydrolysis resistance.
In this paper we describe the synthesis and affinity toward the mu-opioid receptor of some tetrapeptides obtained from endomorphin-1, H-Tyr-Pro-Trp-Phe-NH(2) (1), by substituting each amino acid in turn with its homologue. The ability to bind mu-opioid receptors depends on the beta-amino acid, and in particular 4, which contains beta-L-Pro, has a K(I) in the nanomolar range. The peptides 4 and 5 are significantly more resistant to enzymatic hydrolysis than 1. The same compounds, as well as the mu-opioid receptor agonist DAMGO, produced a concentration-dependent inhibition of forskolin-stimulated cyclic AMP formation, thus behaving as mu-opioid agonists. These features suggest that this novel class of endomorphin-1 analogues may represent suitable candidates for the in vivo investigation as potential mu-opioid receptor agonists. Topics: Animals; Binding, Competitive; Brain; Carboxypeptidases; Cathepsin A; CD13 Antigens; Chymotrypsin; Cyclic AMP; Hydrolysis; In Vitro Techniques; Oligopeptides; Proline; Radioligand Assay; Rats; Receptors, Opioid, mu; Stereoisomerism; Tumor Cells, Cultured | 2002 |