Quantitative structure-activity relationship modeling of renin-inhibiting dipeptides

Area of Science:

• Medicinal Chemistry
• Computational Chemistry
• Pharmacology

Background:

• Renin is a key enzyme in the renin-angiotensin-aldosterone system, regulating blood pressure.
• Natural dipeptides offer a potential source for developing novel antihypertensive agents.
• Understanding structure-activity relationships is crucial for designing effective renin inhibitors.

Purpose of the Study:

• To develop quantitative structure-activity relationship (QSAR) models for predicting the renin-inhibitory activity of natural dipeptides.
• To identify key structural features of dipeptides associated with potent renin inhibition.
• To guide the synthesis and evaluation of novel antihypertensive dipeptides.

Main Methods:

• Partial least squares regression (PLSR) was employed to build predictive models.
• Amino acid descriptors based on 3- and 5-z scales were utilized.
• Model validation included cross-validation and permutation tests.
• In vitro renin inhibition assays were performed to confirm predicted activity.

Main Results:

• PLSR models explained 71.6% and 75.2% of the variance in renin-inhibitory activity.
• Optimal dipeptide structures feature small, hydrophobic N-terminal amino acids and bulky C-terminal amino acids.
• Four predicted potent inhibitors (IW, LW, VW, AW) were synthesized; IW and LW showed significant renin inhibition.
• Observed activities did not correlate with angiotensin-converting enzyme inhibition.

Conclusions:

• Specific amino acid properties, such as size and hydrophobicity, significantly influence renin inhibition.
• The dipeptide isoleucine-tryptophan (IW) demonstrates promising antihypertensive potential.
• IW serves as a valuable template for developing advanced, low-molecular-weight antihypertensive peptides and peptidomimetics.