beta-cyclodextrin as an additive to improve the thermostability of Yarrowia lipolytica Lipase 2: Experimental and simulation insights

摘要

The influence of,B-cyclodextrin on the thermostability of Yarrowia lipolytica Lipase 2 (YLLIP2) has been simultaneously studied by in vitro experiments and molecular simulations. Both circular dichroism (CD) measurement and molecular dynamic (MD) simulation results verified that the content of the alpha-helix increased in the presence of beta-cyclodextrin. Additionally, the reduction of the mean square fluctuation (RMSF) successfully demonstrated that beta-cyclodextrin, as additive, restored the thermosensitive region of YLLIP2 (SER 90-VAL 125, SER 146-ASP 153 and GLN 282-GLY 287) over the optimum temperature (333 K) in MD simulations. Subsequently, further researches exhibited that the,B-cyclodextrin molecule connected the separated region (SER 90-VAL 125 and LYS 176-210 ASN) of YLLIP2 through interactions with surface polar residues. The beta-cyclodextrin molecule was like a bridge anchoring THR 117 and ASN 178, ASP 121 and LYS 203, THR 117 and GLU 209 at 313 K, 323 K and 333 K, respectively. The present study identities the effect of beta-cyclodextrin on thermostability of YLLIP2 at molecular level and facilitates the extensive application of YLLIP2 in bio-catalysis. (C) 2016 Published by Elsevier B.V. on behalf of Taiwan Institute of Chemical Engineers.