TY - JOUR
T1 - Betaine-homocysteine methyltransferase is a developmentally regulated enzyme crystallin in rhesus monkey lens
AU - Rao, P. Vasantha
AU - Garrow, Timothy A.
AU - John, Faith
AU - Garland, Donita
AU - Millian, Norman S.
AU - Zigler, J. Samuel
PY - 1998/11/13
Y1 - 1998/11/13
N2 - We describe herein the characterization of a major 45-kDa protein from the soluble βH-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 2.1.1.5), 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 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 (ψ-crystallin). This is the first enzyme crystallin to be found in primate lenses.
AB - We describe herein the characterization of a major 45-kDa protein from the soluble βH-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 2.1.1.5), 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 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 (ψ-crystallin). This is the first enzyme crystallin to be found in primate lenses.
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U2 - 10.1074/jbc.273.46.30669
DO - 10.1074/jbc.273.46.30669
M3 - Article
C2 - 9804840
AN - SCOPUS:0032514889
SN - 0021-9258
VL - 273
SP - 30669
EP - 30674
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 46
ER -