Precipitation of crystallins from young rat lens by endogenous calpain

Thomas (Tom) Shearer, M. Shih, M. Azuma, Larry David

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

The purpose of these experiments was to study the mechanism for precipitation of lens crystallins in cataract. An in vitro model was developed to activate the endogenous protease calpain II in the soluble proteins from young rat lens by addition of calcium in the presence of 120 mm KCl. Light-scattering, insoluble proteins were produced approximately 4-6 days after calpain II activation. Results showed that proteolysis was caused by activation of lens calpain II, proteolysis preceded precipitation by several days, and α-crystallin acted as a molecular chaperone against precipitation of crystallins caused by proteolysis. These data supported our hypothesis that calpain-induced proteolysis of the N-terminal arms of β-crystallin polypeptides leads to a loss of normal oligomerization of β-crystallin polypeptides and formation of abnormal insoluble aggregates, possibly stabilized by hydrophobic interactions.

Original languageEnglish (US)
Pages (from-to)141-150
Number of pages10
JournalExperimental Eye Research
Volume61
Issue number2
DOIs
StatePublished - 1995

Fingerprint

Crystallins
Calpain
Lenses
Proteolysis
Peptides
Molecular Chaperones
Hydrophobic and Hydrophilic Interactions
Cataract
Proteins
Calcium
Light

Keywords

  • calpain
  • cataract
  • crystallins
  • insolubilization
  • lens
  • light scatter
  • proteolysis
  • rat

ASJC Scopus subject areas

  • Ophthalmology
  • Cellular and Molecular Neuroscience
  • Sensory Systems

Cite this

Precipitation of crystallins from young rat lens by endogenous calpain. / Shearer, Thomas (Tom); Shih, M.; Azuma, M.; David, Larry.

In: Experimental Eye Research, Vol. 61, No. 2, 1995, p. 141-150.

Research output: Contribution to journalArticle

@article{a7bf0d7332704584a5d4c70b7e6f9b84,
title = "Precipitation of crystallins from young rat lens by endogenous calpain",
abstract = "The purpose of these experiments was to study the mechanism for precipitation of lens crystallins in cataract. An in vitro model was developed to activate the endogenous protease calpain II in the soluble proteins from young rat lens by addition of calcium in the presence of 120 mm KCl. Light-scattering, insoluble proteins were produced approximately 4-6 days after calpain II activation. Results showed that proteolysis was caused by activation of lens calpain II, proteolysis preceded precipitation by several days, and α-crystallin acted as a molecular chaperone against precipitation of crystallins caused by proteolysis. These data supported our hypothesis that calpain-induced proteolysis of the N-terminal arms of β-crystallin polypeptides leads to a loss of normal oligomerization of β-crystallin polypeptides and formation of abnormal insoluble aggregates, possibly stabilized by hydrophobic interactions.",
keywords = "calpain, cataract, crystallins, insolubilization, lens, light scatter, proteolysis, rat",
author = "Shearer, {Thomas (Tom)} and M. Shih and M. Azuma and Larry David",
year = "1995",
doi = "10.1016/S0014-4835(05)80033-8",
language = "English (US)",
volume = "61",
pages = "141--150",
journal = "Experimental Eye Research",
issn = "0014-4835",
publisher = "Academic Press Inc.",
number = "2",

}

TY - JOUR

T1 - Precipitation of crystallins from young rat lens by endogenous calpain

AU - Shearer, Thomas (Tom)

AU - Shih, M.

AU - Azuma, M.

AU - David, Larry

PY - 1995

Y1 - 1995

N2 - The purpose of these experiments was to study the mechanism for precipitation of lens crystallins in cataract. An in vitro model was developed to activate the endogenous protease calpain II in the soluble proteins from young rat lens by addition of calcium in the presence of 120 mm KCl. Light-scattering, insoluble proteins were produced approximately 4-6 days after calpain II activation. Results showed that proteolysis was caused by activation of lens calpain II, proteolysis preceded precipitation by several days, and α-crystallin acted as a molecular chaperone against precipitation of crystallins caused by proteolysis. These data supported our hypothesis that calpain-induced proteolysis of the N-terminal arms of β-crystallin polypeptides leads to a loss of normal oligomerization of β-crystallin polypeptides and formation of abnormal insoluble aggregates, possibly stabilized by hydrophobic interactions.

AB - The purpose of these experiments was to study the mechanism for precipitation of lens crystallins in cataract. An in vitro model was developed to activate the endogenous protease calpain II in the soluble proteins from young rat lens by addition of calcium in the presence of 120 mm KCl. Light-scattering, insoluble proteins were produced approximately 4-6 days after calpain II activation. Results showed that proteolysis was caused by activation of lens calpain II, proteolysis preceded precipitation by several days, and α-crystallin acted as a molecular chaperone against precipitation of crystallins caused by proteolysis. These data supported our hypothesis that calpain-induced proteolysis of the N-terminal arms of β-crystallin polypeptides leads to a loss of normal oligomerization of β-crystallin polypeptides and formation of abnormal insoluble aggregates, possibly stabilized by hydrophobic interactions.

KW - calpain

KW - cataract

KW - crystallins

KW - insolubilization

KW - lens

KW - light scatter

KW - proteolysis

KW - rat

UR - http://www.scopus.com/inward/record.url?scp=0029050241&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029050241&partnerID=8YFLogxK

U2 - 10.1016/S0014-4835(05)80033-8

DO - 10.1016/S0014-4835(05)80033-8

M3 - Article

C2 - 7556477

AN - SCOPUS:0029050241

VL - 61

SP - 141

EP - 150

JO - Experimental Eye Research

JF - Experimental Eye Research

SN - 0014-4835

IS - 2

ER -