title: C-peptide inhibitors of Ebola virus glycoprotein-mediated cell entry: effects of conjugation to cholesterol and side chain-side chain crosslinking.
abstract: We previously described potent inhibition of Ebola virus entry by a 'C-peptide' based on the GP2 C-heptad repeat region (CHR) targeted to endosomes ('Tat-Ebo'). Here, we report the synthesis and evaluation of C-peptides conjugated to cholesterol, and Tat-Ebo analogs containing covalent side chain-side chain crosslinks to promote α-helical conformation. We found that the cholesterol-conjugated C-peptides were potent inhibitors of Ebola virus glycoprotein (GP)-mediated cell entry (~10(3)-fold reduction in infection at 40 μM). However, this mechanism of inhibition is somewhat non-specific because the cholesterol-conjugated peptides also inhibited cell entry mediated by vesicular stomatitis virus glycoprotein G. One side chain-side chain crosslinked peptide had moderately higher activity than the parent compound Tat-Ebo. Circular dichroism revealed that the cholesterol-conjugated peptides unexpectedly formed a strong α-helical conformation that was independent of concentration. Side chain-side chain crosslinking enhanced α-helical stability of the Tat-Ebo variants, but only at neutral pH. These result provide insight into mechanisms of C-peptide inhibiton of Ebola virus GP-mediated cell entry.
authors: Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
authors: Chelsea D
authors: CD
authors: Higgins
authors: Jayne F
authors: JF
authors: Koellhoffer
authors: Kartik
authors: K
authors: Chandran
authors: Jonathan R
authors: JR
authors: Lai
mesh_terms: D000595:Amino Acid Sequence; D002096:C-Peptide / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002784:Cholesterol / Q000737:chemistry*; D002942:Circular Dichroism; D003432:Cross-Linking Reagents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D029043:Ebolavirus / Q000187:drug effects*; D015394:Molecular Structure; D014759:Viral Envelope Proteins / Q000037:antagonists & inhibitors; D053586:Virus Internalization / Q000187:drug effects*
chemical_list: D002096:C-Peptide; D003432:Cross-Linking Reagents; D014759:Viral Envelope Proteins; D002784:Cholesterol
keywords: C-peptide; Ebola virus; Hemorrhagic fever; Peptide design; Viral membrane fusion
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