Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/106972
Title: Tryptophan-dependent membrane interaction and heteromerization with the internal fusion peptide by the membrane proximal external region of SARS-CoV spike protein
Authors: Liao, Ying
Zhang, Si Min
Neo, Tuan Ling
Tam, James P.
Keywords: DRNTU::Science::Biological sciences::Biochemistry
Issue Date: 2015
Source: Liao, Y., Zhang, S. M., Neo, T. L., & Tam, J. P. (2015). Tryptophan-dependent membrane interaction and heteromerization with the internal fusion peptide by the membrane proximal external region of SARS-CoV spike protein. Biochemistry, 54(9), 1819-1830.
Series/Report no.: Biochemistry
Abstract: The spike (S) protein of severe acute respiratory syndrome-associated CoV (SARS-CoV) mediates membrane fusion and viral entry. These events involve structural rearrangements, including heteromerization between two heptad repeats (HR1 and HR2) to form a trimer of dimers as a six-helix bundle (6-HB), a quaternary protein structure that brings two distant clusters of hydrophobic sequences into the proximity of each other, the internal fusion peptide (IFP) preceding HR1, and the highly conserved tryptophan (Trp)-rich membrane proximal external region (MPER) following HR2. Here, we show that MPER can undergo self-oligomerization and heteromerization with IFP, events that are Trp-dependent. To delineate the roles of Trp residues of MPER in forming these quaternary structures and interacting with membranes, we employed a panel of synthetic peptides: MPER peptide (M-wt) and its alanine (Ala) and phenylalanine (Phe) analogues. Ala substitutions of Trp inhibited its association with cellular membranes. Chemical cross-linking experiments showed that M-wt can self-interact to form oligomers and cross-interact with IFP23, a synthetic IFP peptide, to form a heterohexamer. In comparison, little high-order oligomer was formed between M-wt and fusion peptide. The specific interaction between M-wt and IFP23 was confirmed by immunofluorescence staining experiments. In aqueous solutions, both M-wt and IFP23 displayed random secondary structures that became helical in hydrophobic solvents. Triple-Ala substitutions of Trp in M-wt, but not the corresponding triple-Phe analogue, disrupted oligomerization of M-wt and hetero-oligomerization of M-wt with IFP23. Overall, our results show that Trp residues of MPER play a key role in maintaining the structure and functions of MPER, allowing it to interact with IFP to form a MPER–IFP heteromer, a putative quaternary structure extending from the 6-HB, and function in membrane fusion. Finally, we showed that a MPER peptide could serve as an inhibitor in the entry process.
URI: https://hdl.handle.net/10356/106972
http://hdl.handle.net/10220/25245
DOI: 10.1021/bi501352u
Rights: © 2015 American Chemical Society. This is the author created version of a work that has been peer reviewed and accepted for publication by Biochemistry, American Chemical Society. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1021/bi501352u].
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:SBS Journal Articles

Google ScholarTM

Check

Altmetric


Plumx

Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.