Cataract as a Protein‐Aggregation Disease

Wang, Yongting; King, Jonathan

doi:10.1002/9780470572702.ch22

Protein Misfolding Diseases 2010

DOI: 10.1002/9780470572702.ch22

|View full text |Cite

Cataract as a Protein‐Aggregation Disease

Yongting Wang

Jonathan King

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2011

2014

Publication Types

Select...

Article6

Relationship

Self Cite2

Independent4

Authors

Journals

Cited by 8 publications

(32 citation statements)

References 173 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ataracts are a protein misfolding disease caused by the aggregation of lens crystallin proteins into insoluble deposits that blur vision (1,2). Because these proteins are not regenerated, damage from UV radiation, oxidative stress, and other chemical modifications accumulates with time (1,2).…”

mentioning

confidence: 99%

“…Because these proteins are not regenerated, damage from UV radiation, oxidative stress, and other chemical modifications accumulates with time (1,2). As a result, over 50% of the population over 55 develops age-related cataracts (2).…”

mentioning

confidence: 99%

“…As a result, over 50% of the population over 55 develops age-related cataracts (2). Additionally, numerous mutations that destabilize crystallin protein folds are linked to inherited and juvenile-onset cataracts (1). Although the causative factors associated with this disease are known, the structures of the aggregates and the mechanisms by which they form are unknown.…”

mentioning

confidence: 99%

“…1) (25). Numerous modes of aggregation have been proposed for the two-domain structure, including amorphous precipitation, domain-swap oligomerization, and amyloid fibril formation (1,26,27). In vitro, fibrillar deposits of γ-crystallins are created by UV damage, low pH, and chemical and thermal denaturation, although it is unclear to what extent each form (or others) contribute to in vivo cataracts (1,(27)(28)(29).…”

mentioning

confidence: 99%

“…Although there is no domain-specific structural information in This article is a PNAS Direct Submission. 1 To whom correspondence should be addressed. E-mail: zanni@chem.wisc.edu.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Two-dimensional IR spectroscopy and segmental ¹³ C labeling reveals the domain structure of human γD-crystallin amyloid fibrils

Moran

Woys

Buchanan

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

128

307

View full text Add to dashboard Cite

The structural eye lens protein γD-crystallin is a major component of cataracts, but its conformation when aggregated is unknown. Using expressed protein ligation, we uniformly 13 C labeled one of the two Greek key domains so that they are individually resolved in two-dimensional (2D) IR spectra for structural and kinetic analysis. Upon acid-induced amyloid fibril formation, the 2D IR spectra reveal that the C-terminal domain forms amyloid β-sheets, whereas the N-terminal domain becomes extremely disordered but lies in close proximity to the β-sheets. Two-dimensional IR kinetics experiments show that fibril nucleation and extension occur exclusively in the C-terminal domain. These results are unexpected because the N-terminal domain is less stable in the monomer form. Isotope dilution experiments reveal that each C-terminal domain contributes two or fewer adjacent β-strands to each β-sheet. From these observations, we propose an initial structural model for γD-crystallin amyloid fibrils. Because only 1 μg of protein is required for a 2D IR spectrum, even poorly expressing proteins can be studied under many conditions using this approach. Thus, we believe that 2D IR and protein ligation will be useful for structural and kinetic studies of many protein systems for which IR spectroscopy can be straightforwardly applied, such as membrane and amyloidogenic proteins. C ataracts are a protein misfolding disease caused by the aggregation of lens crystallin proteins into insoluble deposits that blur vision (1, 2). Because these proteins are not regenerated, damage from UV radiation, oxidative stress, and other chemical modifications accumulates with time (1, 2). As a result, over 50% of the population over 55 develops age-related cataracts (2). Additionally, numerous mutations that destabilize crystallin protein folds are linked to inherited and juvenile-onset cataracts (1). Although the causative factors associated with this disease are known, the structures of the aggregates and the mechanisms by which they form are unknown.Like other protein aggregation diseases such as type II diabetes mellitus and Alzheimer's disease, the molecular structures of proteins in cataracts are difficult to determine. Atomic-level structures have been obtained for some amyloid aggregates of peptides using NMR spectroscopy (3, 4) and X-ray crystallography (5). However, the most widely used techniques for studying aggregate structures and aggregation mechanisms are circular dichroism spectroscopy, fluorescence spectroscopy, and transmission electron microscopy, which provide little detailed structural information. Two-dimensional (2D) IR spectroscopy is emerging as an important tool for studying protein aggregates such as amyloid fibrils (6-8) because it provides bond-by-bond structural resolution on kinetically evolving samples (6, 8-10). Two-dimensional IR spectroscopy probes secondary structure through cross peak couplings and solvent exposure through 2D lineshapes. Its bond-specific structural resolution comes from isotope labeling. Mech...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

“…Although there is no domain-specific structural information in This article is a PNAS Direct Submission. 1 To whom correspondence should be addressed. E-mail: zanni@chem.wisc.edu.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Two-dimensional IR spectroscopy and segmental ¹³ C labeling reveals the domain structure of human γD-crystallin amyloid fibrils

Moran

Woys

Buchanan

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

128

307

View full text Add to dashboard Cite

show abstract

An alternative structural isoform in amyloid‐like aggregates formed from thermally denatured human γD‐crystallin

2014

View full text Add to dashboard Cite

The eye lens protein cD-crystallin contributes to cataract formation in the lens. In vitro experiments show that cD-crystallin has a high propensity to form amyloid fibers when denatured, and that denaturation by acid or UV-B photodamage results in its C-terminal domain forming the b-sheet core of amyloid fibers. Here, we show that thermal denaturation results in sheet-like aggregates that contain cross-linked oligomers of the protein, according to transmission electron microscopy and SDS-PAGE. We use two-dimensional infrared spectroscopy to show that these aggregates have an amyloid-like secondary structure with extended b-sheets, and use isotope dilution experiments to show that each protein contributes approximately one b-strand to each b-sheet in the aggregates. Using segmental 13 C labeling, we show that the organization of the protein's two domains in thermally induced aggregates results in a previously unobserved structure in which both the N-terminal and C-terminal domains contribute to b-sheets. We propose a model for the structural organization of the aggregates and attribute the recruitment of the N-terminal domain into the fiber structure to intermolecular cross linking.

show abstract

Group II archaeal chaperonin recognition of partially folded human γD‐crystallin mutants

et al. 2014

Self Cite

View full text Add to dashboard Cite

The features in partially folded intermediates that allow the group II chaperonins to distinguish partially folded from native states remain unclear. The archaeal group II chaperonin from Methanococcus Mauripaludis (Mm-Cpn) assists the in vitro refolding of the well-characterized bsheet lens protein human cD-crystallin (HcD-Crys). The domain interface and buried cores of this Greek key conformation include side chains, which might be exposed in partially folded intermediates. We sought to assess whether particular features buried in the native state, but absent from the native protein surface, might serve as recognition signals. The features tested were (a) paired aromatic side chains, (b) side chains in the interface between the duplicated domains of HcD-Crys, and (c) side chains in the buried core which result in congenital cataract when substituted. We tested the Mm-Cpn suppression of aggregation of these HcD-Crys mutants upon dilution out of denaturant. Mm-Cpn was capable of suppressing the off-pathway aggregation of the three classes of mutants indicating that the buried residues were not recognition signals. In fact, Mm-Cpn recognized the HcD-Crys mutants better than (wild-type) WT and refolded most mutant HcD-Crys to levels twice that of WT HcD-Crys. This presumably represents the increased population or longer lifetimes of the partially folded intermediates of the mutant proteins. The results suggest that MmCpn does not recognize the features of HcD-Crys tested-paired aromatics, exposed domain interface, or destabilized core-but rather recognizes other features of the partially folded b-sheet conformation that are absent or inaccessible in the native state of HcD-Crys.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Cataract as a Protein‐Aggregation Disease

Cited by 8 publications

References 173 publications

Two-dimensional IR spectroscopy and segmental ¹³ C labeling reveals the domain structure of human γD-crystallin amyloid fibrils

Two-dimensional IR spectroscopy and segmental ¹³ C labeling reveals the domain structure of human γD-crystallin amyloid fibrils

An alternative structural isoform in amyloid‐like aggregates formed from thermally denatured human γD‐crystallin

Group II archaeal chaperonin recognition of partially folded human γD‐crystallin mutants

Contact Info

Product

Resources

About

Cataract as a Protein‐Aggregation Disease

Cited by 8 publications

References 173 publications

Two-dimensional IR spectroscopy and segmental 13 C labeling reveals the domain structure of human γD-crystallin amyloid fibrils

Two-dimensional IR spectroscopy and segmental 13 C labeling reveals the domain structure of human γD-crystallin amyloid fibrils

An alternative structural isoform in amyloid‐like aggregates formed from thermally denatured human γD‐crystallin

Group II archaeal chaperonin recognition of partially folded human γD‐crystallin mutants

Contact Info

Product

Resources

About

Two-dimensional IR spectroscopy and segmental ¹³ C labeling reveals the domain structure of human γD-crystallin amyloid fibrils

Two-dimensional IR spectroscopy and segmental ¹³ C labeling reveals the domain structure of human γD-crystallin amyloid fibrils