Role of proteolysis in lenses: A review

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

It has been suggested that proteases are involved in removal of damaged or obsolete proteins and/or that the activation of proteases could contribute to cataract formation. This review summarizes the properties of several recently studied lens endopeptidases including: trypsin-like protease, multicatalytic endopeptidase complex, membrane bound proteases, and calpain. Properties discussed include composition, substrate specificity, distribution, changes in activity during aging, and regulation. Additionally, properties of the lens ubiquitin conjugation system are reviewed. When possible, an attempt was made to relate these findings to whether the lens proteolytic activity was involved in clearing damaged proteins, or whether it could contribute to cataract formation. Clearing of damaged or obsolete lens proteins may involve the participation of several protease activities. Findings suggest that lens protease activities are lost at variable rates during aging, and differ in concentration between species. It was concluded that the consequence of proteolytic activity in the lens may depend closely on the compliment of proteolytic activities found. For instance, proteases causing only partial degradation of lens proteins may predominate in lenses undergoing cataract formation, while proteases assisting in the removal of partially degraded proteins are lost. The partially degraded lens proteins, as well as other denatured lens proteins, may then accumulate and lead to cataract formation.

Original languageEnglish (US)
Pages (from-to)725-747
Number of pages23
JournalLens and Eye Toxicity Research
Volume6
Issue number4
StatePublished - 1989

Fingerprint

Lenses
Proteolysis
Peptide Hydrolases
Crystallins
Cataract
Endopeptidases
Proteins
Calpain
Proteasome Endopeptidase Complex
Ubiquitin
Substrate Specificity
Trypsin
Membranes

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems

Cite this

Role of proteolysis in lenses : A review. / David, Larry; Shearer, Thomas (Tom).

In: Lens and Eye Toxicity Research, Vol. 6, No. 4, 1989, p. 725-747.

Research output: Contribution to journalArticle

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