title: Evaluation of structure and hydrolysis activity of Candida rugosa Lip7 in presence of sub-/super-critical CO₂.
abstract: This work aimed to assess the effect of sub-/super-critical CO₂ on the structure and activity of Candida rugosa Lip7 (CRL7) in its solution form. The structure was examined by SDS-PAGE gel electrophoresis, circular dichroism (CD) and fluorescence spectra photometry. Results revealed that the primary structure remained intact after sub-/super-critical CO₂ treatment, and the secondary structure altered at the pressure of 10 MPa and temperature 40°C for 30 min incubation, but it was reflex to its native form with increasing incubation time up to 150 min under 10 MPa and 40 °C. Meanwhile, the tertiary structure via fluorescence spectra analysis showed that the intensity of the maximal emission wavelength at 338 nm decreased under the conditions of 10 MPa and 40°C for 150 min. Furthermore, the residue hydrolysis activity and kinetics constants (V(max) and K(m)) of CRL7 treated with sub-/super-critical CO₂ were also investigated. In cases of 6 MPa and 35°C, or 10 MPa and 40°C for 30 min, activity variance of CRL7 was maybe caused by its secondary structure alteration. But in case of 10 MPa and 40°C for 150 min, the tertiary structure change was perhaps responsibility for CRL7 activity enhancement.
authors.affiliation: Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China. liuyunprivate@sian.com
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.forename: Dawei
authors.initials: D
authors.lastname: Chen
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Yunjun
authors.initials: Y
authors.lastname: Yan
mesh_terms: D001709:Biotechnology; D002175:Candida / Q000201:enzymology*; D002245:Carbon Dioxide / Q000494:pharmacology; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism*; D006868:Hydrolysis; D006874:Hydrostatic Pressure; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation / Q000187:drug effects; D017433:Protein Structure, Secondary / Q000187:drug effects; D017434:Protein Structure, Tertiary / Q000187:drug effects; D013050:Spectrometry, Fluorescence; D013696:Temperature
chemical_list: D005656:Fungal Proteins; D007527:Isoenzymes; D002245:Carbon Dioxide; D008049:Lipase