Background: D-beta-aspartic acid residues, which are biologically uncommon, have been reported to accumulate in various proteins of the living body with age. In the present study, D-beta-aspartic acid-containing proteins were found to be localised in pingueculae, which represent one of the most prominent age-related ocular changes.
Methods: Surgical specimens of conjunctivae with or without pingueculae were obtained from eight patients. Immunohistochemical localisation of D-beta-aspartic acid-containing proteins was performed using a polyclonal antibody against D-beta-aspartic acid-containing peptides.
Results: Strong immunoreactivity to D-beta-aspartic acid-containing peptides was detected in the subepithelial amorphous materials of all surgical specimens with pingueculae. In contrast, no immunoreactivity to D-beta-aspartic acid-containing peptides was detected in the specimens without pingueculae.
Conclusions: Pingueculae are thought to be aggregates of proteins that contain D-beta-aspartic acid residues. It is known that the conversion of L- to D-aspartyl residues is accelerated by ultraviolet irradiation. In addition, D-beta-aspartic acid-containing proteins, in general, tend to aggregate with each other and accumulate in the tissues. These facts indicate that ultraviolet irradiation-induced racemisation of aspartic acid is closely related to the development of pingueculae.
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http://dx.doi.org/10.1136/bjo.2007.135889 | DOI Listing |
J Ophthalmol
May 2019
Department of Ophthalmology and Visual Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8551, Japan.
Purpose: To investigate the effect of ocular hypertension-induced isomerization of aspartic acid in retinal proteins.
Methods: Adult Wistar rats with ocular hypertension were used as an experimental model. D--aspartic acid-containing proteins were isolated by SDS-PAGE and western blot with an anti-D--aspartic acid antibody and identified by liquid chromatography-mass spectrometry analysis.
J Pharm Biomed Anal
December 2015
Research Reactor Institute, Kyoto University, Osaka, Japan.
Biologically uncommon D-β-aspartic acid (D-β-Asp) residues have been reported to accumulate in organs affected by age-related disorders. In the present study, we investigated the localization of D-β-Asp-containing proteins in cases of pterygium, one of the most prominent age-related ocular conditions. Immunohistochemical localization of D-β-Asp-containing proteins was investigated in surgical specimens of pterygium from 20 patients and control specimens from 10 patients.
View Article and Find Full Text PDFBr J Ophthalmol
August 2012
Department of Ophthalmology, Tsukuba University Institute of Clinical Medicine, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8575, Japan.
Purpose: Gelatinous drop-like corneal dystrophy (GDLD), also known as familial subepithelial corneal amyloidosis, is an autosomal recessive disorder that causes progressive corneal opacity due to accumulation of amyloid fibrils in the corneal stroma. Genetic analyses have revealed that a mutation in membrane component chromosome 1 surface marker 1 gene is responsible for GDLD. However, the mechanism of amyloid formation in the corneal stroma remains unclear.
View Article and Find Full Text PDFChem Biodivers
June 2010
Department of Ophthalmology, Tsukuba University Institute of Clinical Medicine, Tennoudai 1-1-1, Tsukuba Ibaraki 305-8575, Japan.
Transparency is essential for eyes, which serve as cameras. However, decreased transparency caused by accumulation of abnormal proteins is commonly observed especially in elderly people. However, the mechanism of accumulation of abnormal proteins in various ocular diseases is still unclear.
View Article and Find Full Text PDFBr J Ophthalmol
July 2009
Department of Ophthalmology, Tsukuba University Institute of Clinical Medicine, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8575, Japan.
Aim: Biologically uncommon D-beta-aspartic acid (D-beta-Asp) accumulates in the body with age and is involved in the ageing process. In the present study, the localisation of D-beta-Asp-containing proteins was investigated in surgical specimens with climatic droplet keratopathy (CDK), one of the ocular changes related to the ageing process.
Methods: Immunohistochemical localisation of D-beta-Asp-containing proteins using polyclonal antibodies raised against D-beta-Asp-containing peptides was examined in three corneas with CDK, three corneas with interstitial keratitis, six corneas with bullous keratopathy, and three corneas without any corneal diseases.
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