Purification and Partial Characterization of β-Glucosidase in Chayote (Sechium edule)

Abstract

β-Glucosidase (EC 3.2.1.21) is a prominent member of the GH1 family of glycoside hydrolases. The properties of this β-glucosidase appear to include resistance to temperature, urea, and iodoacetamide, and it is activated by 2-ME, similar to other members. β-Glucosidase from chayote (Sechium edule) was purified by ionic-interchange chromatography and molecular exclusion chromatography. Peptides detected by LC-ESI-MS/MS were compared with other β-glucosidases using the BLAST program. This enzyme is a 116 kDa protein composed of two sub-units of 58 kDa and shows homology with Cucumis sativus β-glucosidase (NCBI OPEN ACCESSMolecules 2015, 20 19373 reference sequence XP_004154617.1), in which seven peptides were found with relative masses ranging from 874.3643 to 1587.8297. The stability of β-glucosidase depends on an initial concentration of 0.2 mg/mL of protein at pH 5.0 which decreases by 33% in a period of 30 h, and then stabilizes and is active for the next 5 days (pH 4.0 gives similar results). One hundred μg/mL β-D-glucose inhibited β-glucosidase activity by more than 50%. The enzyme had a Km of 4.88 mM with p-NPG and a Kcat of 10,000 min −1. The optimal conditions for the enzyme require a pH of 4.0 and a temperature of 50 °C.

Assessments on the catalytic and kinetic properties of beta-glucosidase isolated from a highly efficient antagonistic fungus Trichoderma harzianum

“…Noteworthily, the estimated molecular mass of the purified β-glucosidase T12 was found comparable with those produced by Pseudomonas purpurogenous KJS 506 (89.6 kDa), T. harzianum T3 (98 kDa) and T. viride (99 kDa) (JEYA et al, 2010;RAMANI et al, 2012) although its molecular mass was a slightly lower as compared to βglucosidase from Sechium edule (116 kDa) (MATEOS et al, 2015). The 16S rDNA nucleotide sequence of T. harzianum T12 was deposited in the GenBank database with accession number KY004113.…”

“…Additionally, interaction between monovalent ions and β-glucosidases can displace the hydrogen atom in disulphide and consequently altering the folding of the protein structure. These changes can effectively inhibit activity of some enzymes (MATEOS et al, 2015).…”

Aggregation and Molecular Properties of β-Glucosidase Isoform II in Chayote (Sechium edule)

“…Previously, the purification and partial characterization of fraction I (isoform I) of β-glucosidase from chayote was performed [10]. The present study evaluates work isolation and purification, properties, and which could be classified in the GH1 family and aggregation characteristics of β-glucosidase isoform II.…”

“…β-Glucosidase from Sechium edule [10] shows sililarities with the Cucurbitaceae family ones, particularly with those from Cucurbita moschata (squash) and Cucumis sativus (cucumber) [11]. This is indicated by the found partial sequence of amino acids that is identical to one of its fragments, as well as its specificity to the substrate.…”

“…The present study evaluates work isolation and purification, properties, and which could be classified in the GH1 family and aggregation characteristics of β-glucosidase isoform II. The juice of epicarp and mesocarp in chayote has a physiological pH 6.8 with 4.2 times more protein and 2.6 times more specific activity than in the conditions used in the extraction of isoform I [10]. Likewise, the procedure to isolate and purify isoform II has been modified, its composition, partial sequence of amino acids, identity with other members of the Cucurbitaceae family, kinetics, and the presence of molecular aggregates are shown.…”