Funastrain c II: A Cysteine Endopeptidase Purified from the Latex of Funastrum clausum

Abstract

A cysteine endopeptidase, named funastrain c II, was isolated and characterized from the latex of Funastrum clausum (Asclepiadaceae). The molecular mass (mass spectrometry) of the protease was 23.636 kDa. The analysis of funastrain c II by SDS-PAGE revealed a single polypeptide chain. The enzyme showed a remarkable stability of its caseinolytic activity after incubation at temperatures as high as 70 degrees C. Inhibition and activation assays indicated the cysteinic nature of the funastrain c II catalytic site. The optimum pH of funastrain c II enzymatic activity varied according to the substrate used (9.0-10.0 for casein and 6.2-6.8 for PFLNA). Kinetic parameters were determined for N-alpha-CBZ-Ala p-nitrophenyl ester (Km = 0.0243 mM, kcat = 1.5 s(-1)) and L-pyroglutamyl-L-phenylalanyl-L-leucine-p-nitroanilide (PFLNA; KM = 0.1011 mM, kcat = 0.9 s(-1)). The N-terminal sequence of funastrain c II showed considerable similarity to other proteases isolated from latex of different Asclepiadaceae species as well as to other cysteine proteinases belonging to the papain family.

A novel form of ficin from Ficus carica latex: Purification and characterization

“…10, ficin E presented a pH optimum at about 6.3 and a temperature optimum at about 55°C. Similar values were reported for other cysteine proteases (Kundu et al, 2000;Singh et al, 2002;Patel and Jagannadham, 2003;Morcelle et al, 2004;Kongkerd et al, 2008;Homaei, et al 2010;Torres et al, 2013).…”

Peptide Mass Fingerprinting and N-Terminal Amino Acid Sequencing of Glycosylated Cysteine Protease of Euphorbia nivulia Buch.-Ham.

“…Similar molecular pattern was also recorded in the molecular mass measurement of Funastrain CII [13]. The resulted molecular mass, that is, 43.67 kDa is very close to those of other peptidase belonging to cysteine protease family for example cysteine proteases of Vigna mungo , Curcuma longa , Taenia crassiceps , Allomyces aebuscula , Triticum arstivum , Haemonchus contortus , and Gymnophalloides seoi [12].…”

Characterization of Thermo‐ and Detergent Stable Antigenic Glycosylated Cysteine Protease of Euphorbia nivulia Buch.‐Ham. and Evaluation of Its Ecofriendly Applications

“…It may contain a variety of cellular components, like nuclei, mitochondria, ribosome-like particles, and lysosome analogues. Agglomerative low density materials, such as various enzymes, terpenes, alkaloids, vitamins, carbohydrates, lipids, and free amino acids have been identified among the components [1]. The characteristic feature of plant from Euphorbiaceae , Apocynaceae , Moraceae , Asclepiadaceae , Sapotaceae , Caricaceae, and Convolvulaceae families has latex secreting properties.…”