title: Purification and Characterization of a Novel Redox-Regulated Isoform of Myrosinase (β-Thioglucoside Glucohydrolase) from Lepidium latifolium L.
abstract: Myrosinase (ExPASy entry EC 3.2.1.147) is involved in the hydrolysis of glucosinolates to isothiocyanates, nitriles, and thiocyanates that are responsible for various ecological and health benefits. Myrosinase was purified from the leaves of Lepidium latifolium, a high-altitude plant, to homogeneity in a three-step purification process. Purified enzyme exists as dimer in native form (∼160 kDa) with a subunit size of ∼70 kDa. The enzyme exhibited maximum activity at pH 6.0 and 50 °C. With sinigrin as substrate, the enzyme showed Km and Vmax values of 171 ± 23 μM and 0.302 μmol min(-1) mg(-1), respectively. The enzyme was found to be redox-regulated, with an increase in Vmax and Kcat in the presence of GSH. Reduced forms of the enzyme were found to be more active. This thiol-regulated kinetic behavior of myrosinase signifies enzyme's strategy to fine-tune its activity in different redox environments, thus regulating its biological effects.
authors.affiliation: Biodiversity and Applied Botany Division, ‡Formulation and Drug Development Division, and §Academy of Scientific and Innovative Research, Indian Institute of Integrative Medicine (CSIR) , Canal Road, Jammu, Jammu and Kashmir 180001, India.
authors.forename: Rohini
authors.initials: R
authors.lastname: Bhat
authors.affiliation: Biodiversity and Applied Botany Division, ‡Formulation and Drug Development Division, and §Academy of Scientific and Innovative Research, Indian Institute of Integrative Medicine (CSIR) , Canal Road, Jammu, Jammu and Kashmir 180001, India.
authors.forename: Tarandeep
authors.initials: T
authors.lastname: Kaur
authors.affiliation: Biodiversity and Applied Botany Division, ‡Formulation and Drug Development Division, and §Academy of Scientific and Innovative Research, Indian Institute of Integrative Medicine (CSIR) , Canal Road, Jammu, Jammu and Kashmir 180001, India.
authors.forename: Manu
authors.initials: M
authors.lastname: Khajuria
authors.affiliation: Biodiversity and Applied Botany Division, ‡Formulation and Drug Development Division, and §Academy of Scientific and Innovative Research, Indian Institute of Integrative Medicine (CSIR) , Canal Road, Jammu, Jammu and Kashmir 180001, India.
authors.forename: Ruchika
authors.initials: R
authors.lastname: Vyas
authors.affiliation: Biodiversity and Applied Botany Division, ‡Formulation and Drug Development Division, and §Academy of Scientific and Innovative Research, Indian Institute of Integrative Medicine (CSIR) , Canal Road, Jammu, Jammu and Kashmir 180001, India.
authors.forename: Dhiraj
authors.initials: D
authors.lastname: Vyas
mesh_terms: D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D029686:Lepidium / Q000737:chemistry / Q000201:enzymology*; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D020033:Protein Isoforms / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D020033:Protein Isoforms; D006026:Glycoside Hydrolases; C022739:thioglucosidase
keywords: enzyme kinetics; enzyme purification; glutathione; myrosinase; redox regulation