Betaine-homocysteine methyltransferase is a developmentally regulated enzyme crystallin in rhesus monkey lens.

Journal Article (Journal Article)

We describe herein the characterization of a major 45-kDa protein from the soluble betaH-crystallin fraction of rhesus monkey (Macaca mulatta) lens. Based on partial peptide sequence, immunoreactivity, and enzymatic activity, this protein has been identified as betaine-homocysteine S-methyltransferase (BHMT: EC, an enzyme that catalyzes the methylation of homocysteine using either betaine or thetins as methyl donors. This protein was found to be expressed abundantly in the nuclear region of the monkey lens, reaching approximately 10% of the total nuclear protein, but was barely detectable in the epithelium and cortex regions of the lens. Because the nucleus represents the early embryonic and fetal stages of lens development, we infer that BHMT expression in the lens of the eye is developmentally regulated. By virtue of its high abundance, BHMT can be considered an enzyme crystallin (psi-crystallin). This is the first enzyme crystallin to be found in primate lenses.

Full Text

Duke Authors

Cited Authors

  • Rao, PV; Garrow, TA; John, F; Garland, D; Millian, NS; Zigler, JS

Published Date

  • November 13, 1998

Published In

Volume / Issue

  • 273 / 46

Start / End Page

  • 30669 - 30674

PubMed ID

  • 9804840

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.273.46.30669


  • eng

Conference Location

  • United States