Self-aggregation of a polyalanine octamer promoted by its C-terminal tyrosine and probed by a strongly enhanced vibrational circular dichroism signal

Title:
Self-aggregation of a polyalanine octamer promoted by its C-terminal tyrosine and probed by a strongly enhanced vibrational circular dichroism signal
Authors:
Measey, Thomas J.; Smith, Kathryn B.; Decatur, Sean M.; Zhao, Liming; Yang, Guoliang; Schwietzer-Stenner, Reinhard
Abstract:
The eight-residue alanine oligopeptide Ac-A4KA2Y-NH2 (AKY8) was found to form amyloid-like fibrils upon incubation at room temperature in acidified aqueous solution at peptide concentrations >10 mM. The fibril solution exhibits an enhanced vibrational circular dichroism (VCD) couplet in the amide I′ band region that is nearly 2 orders of magnitude larger than typical polypeptide/protein signals in this region. The UV-CD spectrum of the fibril solution shows CD in the region associated with the tyrosine side chain absorption. A similar peptide, Ac-A4KA2-NH2 (AK7), which lacks a terminal tyrosine residue, does not aggregate. These results suggest a pivotal role for the C-terminal tyrosine residue in stabilizing the aggregation state of this peptide. It is speculated that interactions between the lysine and tyrosine side chains of consecutive strands in an antiparallel arrangement (e.g., cation−π interactions) are responsible for the stabilization of the resulting fibrils. These results offer considerations and insight regarding the de novo design of self-assembling oligopeptides for biomedical and biotechnological applications and highlight the usefulness of VCD as a tool for probing amyloid fibril formation.
Citation:
Measey, T.J., K.B. Smith, S.M. Decatur, L. Zhao, et al. 2009. "Self-aggregation of a polyalanine octamer promoted by its C-terminal tyrosine and probed by a strongly enhanced vibrational circular dichroism signal." American Chemical Society 131(51): 18218-18219.
Publisher:
American Chemical Society
DATE ISSUED:
2009
Department:
Chemistry
Type:
article
PUBLISHED VERSION:
10.1021/ja908324m
PERMANENT LINK:
http://hdl.handle.net/11282/309087

Full metadata record

DC FieldValue Language
dc.contributor.authorMeasey, Thomas J.en_US
dc.contributor.authorSmith, Kathryn B.en_US
dc.contributor.authorDecatur, Sean M.en_US
dc.contributor.authorZhao, Limingen_US
dc.contributor.authorYang, Guoliangen_US
dc.contributor.authorSchwietzer-Stenner, Reinharden_US
dc.date.accessioned2013-12-23T16:02:02Z-
dc.date.available2013-12-23T16:02:02Z-
dc.date.issued2009en
dc.identifier.citationMeasey, T.J., K.B. Smith, S.M. Decatur, L. Zhao, et al. 2009. "Self-aggregation of a polyalanine octamer promoted by its C-terminal tyrosine and probed by a strongly enhanced vibrational circular dichroism signal." American Chemical Society 131(51): 18218-18219.en_US
dc.identifier.issn0002-7863en_US
dc.identifier.urihttp://hdl.handle.net/11282/309087-
dc.description.abstractThe eight-residue alanine oligopeptide Ac-A4KA2Y-NH2 (AKY8) was found to form amyloid-like fibrils upon incubation at room temperature in acidified aqueous solution at peptide concentrations >10 mM. The fibril solution exhibits an enhanced vibrational circular dichroism (VCD) couplet in the amide I′ band region that is nearly 2 orders of magnitude larger than typical polypeptide/protein signals in this region. The UV-CD spectrum of the fibril solution shows CD in the region associated with the tyrosine side chain absorption. A similar peptide, Ac-A4KA2-NH2 (AK7), which lacks a terminal tyrosine residue, does not aggregate. These results suggest a pivotal role for the C-terminal tyrosine residue in stabilizing the aggregation state of this peptide. It is speculated that interactions between the lysine and tyrosine side chains of consecutive strands in an antiparallel arrangement (e.g., cation−π interactions) are responsible for the stabilization of the resulting fibrils. These results offer considerations and insight regarding the de novo design of self-assembling oligopeptides for biomedical and biotechnological applications and highlight the usefulness of VCD as a tool for probing amyloid fibril formation.en_US
dc.publisherAmerican Chemical Societyen_US
dc.identifier.doi10.1021/ja908324m-
dc.subject.departmentChemistryen_US
dc.titleSelf-aggregation of a polyalanine octamer promoted by its C-terminal tyrosine and probed by a strongly enhanced vibrational circular dichroism signalen_US
dc.typearticleen_US
dc.identifier.journalAmerican Chemical Societyen_US
dc.identifier.volume131en_US
dc.identifier.issue51en_US
dc.identifier.startpage18218en_US
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