The Proteolytic Activity of Philibertia gilliesii Latex. Purification of Philibertain g II

SEQUEIROS C.; TORRES M.J.; NIEVAS M.L.; CAFFINI N.O.; NATALUCCI C.N.; LÓPEZ M.L.I.; TREJO S.A.

APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY

HUMANA PRESS INC

Lugar: Oregon; Año: 2016 vol. 179 p. 332 - 346

0273-2289

The latex from the patagonic plant Philibertia gilliesii Hook. et Arn.(Apocynaceae) is a milky-white suspension containing a proteolytic systemconstituted by several cysteine endopeptidases. A proteolytic preparation(philibertain g) from the latex of P. gilliesii fruits was obtained andcharacterized to evaluate its potential use in bioprocesses. Philibertain gcontained 1.2 g/L protein and a specific (caseinolytic) activity of 7.0 Ucas/mgprotein. It reached 80 % of its maximum caseinolytic activity in the pH 7?10range, retained 80 % of the original activity after 2 h of incubation attemperatures ranging from 25 to 45 °C and could be fully inactivated after 5min at 75 °C. Philibertain g retained 60 % of the initial activity even at 1 MNaCl and was able to hydrolyze proteins from stickwater one, of the main wasteeffluents generated during fishmeal production. Furthermore, as a contributionto the knowledge of the proteolytic system of P. gilliesii, we are reporting the purification of a new peptidase,named philibertain g II (pI 9.4, molecular mass 23,977 Da, N-terminusLPESVDWREKGVVFPXRNQ) isolated from philibertain g through a purification schemeincluding acetone fractionation, cation exchange, molecular exclusionchromatography, and ultrafiltration.