title: The Proteolytic Activity of Philibertia gilliesii Latex. Purification of Philibertain g II.
abstract: The latex from the patagonic plant Philibertia gilliesii Hook. et Arn. (Apocynaceae) is a milky-white suspension containing a proteolytic system constituted by several cysteine endopeptidases. A proteolytic preparation (philibertain g) from the latex of P. gilliesii fruits was obtained and characterized to evaluate its potential use in bioprocesses. Philibertain g contained 1.2 g/L protein and a specific (caseinolytic) activity of 7.0 Ucas/mg protein. It reached 80 % of its maximum caseinolytic activity in the pH 7-10 range, retained 80 % of the original activity after 2 h of incubation at temperatures ranging from 25 to 45 °C and could be fully inactivated after 5 min at 75 °C. Philibertain g retained 60 % of the initial activity even at 1 M NaCl and was able to hydrolyze proteins from stickwater one, of the main waste effluents generated during fishmeal production. Furthermore, as a contribution to 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-terminus LPESVDWREKGVVFPXRNQ) isolated from philibertain g through a purification scheme including acetone fractionation, cation exchange, molecular exclusion chromatography, and ultrafiltration.
authors: CENPAT-CONICET, Centro Nacional Patagónico, Blvd. Brown N° 2915, 9120, Puerto Madryn, Chubut, Argentina.
authors: Cynthia
authors: C
authors: Sequeiros
authors: Centro de Investigaciones y Transferencia del Noroeste de la provincia de Buenos Aires, UNNOBA-CONICET, Junín, Argentina.
authors: María J
authors: MJ
authors: Torres
authors: CENPAT-CONICET, Centro Nacional Patagónico, Blvd. Brown N° 2915, 9120, Puerto Madryn, Chubut, Argentina.
authors: Marina L
authors: ML
authors: Nievas
authors: CIPROVE, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC 711, 1900, La Plata, Argentina.
authors: Néstor O
authors: NO
authors: Caffini
authors: CIPROVE, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC 711, 1900, La Plata, Argentina.
authors: Claudia L
authors: CL
authors: Natalucci
authors: CITEC, Instituto Nacional de Tecnología Industrial, Ciencias de la Salud - Universidad Nacional Arturo Jauretche, Buenos Aires, Argentina. lmiilopez@yahoo.com.ar.
authors: Laura M I
authors: LM
authors: López
authors: Servei de Proteòmicai Biologia Estructural (SePBioEs), Universitat Autònoma de Barcelona, Campus Universitari, 08193 Bellaterra, Cerdanyola del Vallès, Barcelona, Spain.
authors: Sebastián A
authors: SA
authors: Trejo
mesh_terms: D000595:Amino Acid Sequence; D029062:Apocynaceae / Q000737:chemistry*; D002852:Chromatography, Ion Exchange; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007840:Latex / Q000737:chemistry*; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry*; D059748:Proteolysis; D017386:Sequence Homology, Amino Acid
chemical_list: D007840:Latex; D010455:Peptides; D010940:Plant Proteins; D010447:Peptide Hydrolases; D003546:Cysteine Endopeptidases
keywords: Apocynaceae; Chromatography; Cysteine peptidase; Fish protein hydrolysates; Stickwater