Design of inhibitors for human tissue kallikrein using non-natural aromatic and basic amino acids.
We explored the unique substrate specificity of the primary S, subsite of human urinary kallikrein (hK1), which accepts both Phe or Arg synthesizing and assaying peptides derived from Phenylacetyl-Phe-Ser-Arg-EDDnp, a previously described inhibitor with analgesic and anti-inflammatory activities [Emim et al., Br. J. Pharmacol. 130 (2000), 1099-1107]. Phe was substituted by amino acids containing larger aliphatic or aromatic side chains as well as by non-natural basic amino acids, which were designed to combine a large hydrophobic and/or aromatic group with a positively-charged group at their side chains. In general, all peptides with basic amino acids represented better inhibitors than those with hydrophobic amino acids. Furthermore, the S1 subsite specificity proved to be much more selective than the mere distinction between Phe and Arg, for minor differences in the side chains of the non-natural amino acids resulted in major differences in the Ki values. Finally, we present a series of peptides that were assayed as competitive inhibitors for human tissue kallikrein that may lead to the development of novel peptides, which are both more potent and selective.
Pimenta
Daniel C
DC
Department of Biophysics, Escola Paulista de Medicina, Universidade Federal de São Paulo, SP, Brazil.
Melo
Robson L
RL
Caliendo
Giuseppe
G
Santagada
Vincenzo
V
Fiorino
Ferdinando
F
Severino
Beatrice
B
de Nucci
Gilberto
G
Juliano
Luiz
L
Juliano
Maria A
MA
D024322:Amino Acids, Aromatic / Q000737:chemistry / Q000494:pharmacology*; D024361:Amino Acids, Basic / Q000737:chemistry / Q000494:pharmacology*; D001665:Binding Sites; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D020840:Tissue Kallikreins / Q000037:antagonists & inhibitors* / Q000378:metabolism
D024322:Amino Acids, Aromatic; D024361:Amino Acids, Basic; D004791:Enzyme Inhibitors; D020840:Tissue Kallikreins