Molten globule-triggered inactivation of a thermostable and solvent stable lipase in hydrophilic solvents.
The use of lipase in hydrophilic solvent is usually hampered by inactivation. The solvent stability of a recombinant solvent stable lipase isolated from thermostable Bacillus sp. strain 42 (Lip 42), in DMSO and methanol were studied at different solvent-water compositions. The enzymatic activities were retained in up to 45% v/v solvent compositions. The near-UV CD spectra indicated that tertiary structures were perturbed at 60% v/v and above. Far-UV CD in methanol indicated the secondary structure in Lip 42 was retained throughout all solvent compositions. Fluorescence studies indicated formations of molten globules in solvent compositions of 60% v/v and above. The enzyme was able to retain its secondary structures in the presence of methanol; however, there was a general reduction in beta-sheet and an increase in alpha-helix contents. The H-bonding arrangements triggered in methanol and DMSO, respectively, caused different forms of tertiary structure perturbations on Lip 42, despite both showing partial denaturation with molten globule formations.
Hamid
Tengku Haziyamin Tengku Abdul
TH
Department of Microbiology, University Putra Malaysia, Serdang, Selangor, Malaysia.
Rahman
Raja Noor Zaliha Raja Abd
RN
Salleh
Abu Bakar
AB
Basri
Mahiran
M
D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D001407:Bacillus / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D002942:Circular Dichroism; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D004789:Enzyme Activation; D004795:Enzyme Stability; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism; D000432:Methanol / Q000737:chemistry; D017434:Protein Structure, Tertiary; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence
D000817:Anilino Naphthalenesulfonates; D001426:Bacterial Proteins; D012997:Solvents; C027132:1-anilino-8-naphthalenesulfonate; D008049:Lipase; D000432:Methanol; D004121:Dimethyl Sulfoxide