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

- Thermostability of lipase was increased by utilizing β-cyclodextrin.
- Effects of β-cyclodextrin on secondary structure of lipase.
- β-cyclodextrin and enzyme interactions contributing to the thermostability.
- β-cyclodextrin interaction with polar residues of lipase.

The influence of β-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 α-helix increased in the presence of β-cyclodextrin. Additionally, the reduction of the mean square fluctuation (RMSF) successfully demonstrated that β-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 β-cyclodextrin molecule connected the separated region (SER 90-VAL 125 and LYS 176-210 ASN) of YLLIP2 through interactions with surface polar residues. The β-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 β-cyclodextrin on thermostability of YLLIP2 at molecular level and facilitates the extensive application of YLLIP2 in bio-catalysis.

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