Structural and physical?chemical evaluation of bradykinin potentiating peptide and its high soluble supramolecular complex.

The supramolecular interactions between a Bradykinin Potentiating Peptide (BPP10c) and b-cyclodextrin (bCD) have been investigated by using several techniques. These new properties acquired by the inclusion phenomena are important in developing a strategy for pharmaceutical formulation. The BPP10c structural elucidation and its inclusion complex formed have been investigated using Nuclear Magnetic Resonance techniques. The peptide secondary structure was investigated using infrared spectroscopy in solution, Circular Dichroism and NMR. In addition, the thermodynamic parameters of the inclusion process were also evaluated using Isothermal Titration Calorimetry. The results obtained by these physical? chemical techniques suggested a 1:1 complex formed by interaction between the Tryptophan amino acid residue and the bCD cavity. The peptide secondary structure was not substantially modified for the inclusion process. In addition, the inclusion process proved to be spontaneous (DG8 = -2.53 kcal mol-1), with an enthalpy reduction (DH8 = -3.72 kcal mol-1) and a favored entropic variation (TDS8 = -1.19 kcal mol-1)

Bj-PRO-5a and Bj-PRO 10c found at c-type natriuretic peptide precursor of bothrops jararaca change renal function of hypertensive rats.

Proline-rich oligopeptides from Bothrops jararaca (Bj-PROs) produce potent and long-lasting antihypertensive effect through mechanisms that go beyond ACE inhibition. In this study we evaluated the renal function parameters of spontaneously hypertensive rats (SHR) injected with Bj-PRO-5a and -10c (0.47, 71 or 710 nmol/ kg) found in the CNP-precursor of the snake. At 71 and 710 nmol/kg, Bj-PROs increased urinary flow rate (18.1? 43.5%). At 71 nmol/kg, Bj-PRO 5a and 10c elevated sodium excretion (68.1 and 40.9%, respectively) and Bj- PRO-5a also increased urinary sodium/creatinine ratio (56.5%). At 0.47 nmol/kg, Bj-PROs did not change renal function. All doses of Bj-PROs reduced blood pressure (? = ?13 to ?24mmHg). We conclude that Bj-PROs reduce blood pressure and improve renal funct