Unique properties of Zika NS2B-NS3pro complexes as decoded by experiments and MD simulations

Amrita Roy; Liangzhong Lim; Shagun Srivastava; Jianxing Song

that the high dynamics of Zika NS2B-NS3pro complex detected by CD and NMR is mostly resulting from the C-terminal region of Zika NS2B, we cloned and expressed a His-tagged Zika NS2B(48-74) with the C-region deleted. Despite its low expression level and insolubility, by growing many liters of E. coli cells, we managed to purify a sufficient amount of NS2B(48-74) for refolding with NS3pro. Interestingly, NS2B(48-74) is capable of forming a soluble complex with NS3pro (Fig. 1E) . However, its NMR peaks are much more broad even than those of linked NS2B-NS3pro ( Fig. 2A) , most likely due to µs-ms conformational dynamics or/and dynamic aggregation. On the other hand, its intrinsic UV fluorescence spectrum indicates that its four Trp residues are similarly buried as linked and unlinked Zika complexes with the fulllength NS2B (Fig. 2D ). Most interestingly, as judged from its CD spectrum which has the maximal negative signal shifted to 207 nm and has positive signal at 191 nm (Fig. 2E) , this author/funder. All rights reserved. No reuse allowed without permission.