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Identification and characterization of a Pi isoform of glutathione S-transferase (GSTP1) as a zeaxanthin-binding protein in the macula of the human eye.
J Biol Chem. 2004 Nov 19; 279(47):49447-54.JB

Abstract

Uptake, metabolism, and stabilization of xanthophyll carotenoids in the retina are thought to be mediated by specific xanthophyll-binding proteins (XBPs). A membrane-associated XBP was purified from human macula using ion-exchange chromatography followed by gel-exclusion chromatography. Two-dimensional gel electrophoresis showed a prominent spot of 23 kDa and an isoelectric point of 5.7. Using mass spectral sequencing methods and the public NCBI database, it was identified as a Pi isoform of human glutathione S-transferase (GSTP1). Dietary (3R,3'R)-zeaxanthin displayed the highest affinity with an apparent Kd of 0.33 microm, followed by (3R,3'S-meso)-zeaxanthin with an apparent Kd of 0.52 microm. (3R,3'R,6'R)-Lutein did not display any high-affinity binding to GSTP1. Other human recombinant glutathione S-transferase (GST) proteins, GSTA1 and GSTM1, exhibited only low affinity binding of xanthophylls. (3R,3'S-meso)-Zeaxanthin, an optically inactive nondietary xanthophyll carotenoid present in the human macula, exhibited a strong induced CD spectrum in association with human macular XBP that was nearly identical to the CD spectrum induced by GSTP1. Like-wise, dietary (3R,3'R)-zeaxanthin displayed alterations in its CD spectrum in association with GSTP1 and XBP. Other mammalian xanthophyll carrier proteins such as tubulin, high-density lipoprotein, low-density lipoprotein, albumin, and beta-lactoglobulin did not bind zeaxanthins with high affinity, and they failed to induce or alter xanthophyll CD spectra to any significant extent. Immunocytochemistry with an antibody to GSTP1 on human macula sections showed highest labeling in the outer and inner plexiform layers. These results indicate that GSTP1 is a specific XBP in human macula that interacts with (3R,3'S-meso)-zeaxanthin and dietary (3R,3'R)-zeaxanthin in contrast to apparently weaker interactions with (3R,3'R,6'R)-lutein.

Authors+Show Affiliations

Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

15355982

Citation

Bhosale, Prakash, et al. "Identification and Characterization of a Pi Isoform of Glutathione S-transferase (GSTP1) as a Zeaxanthin-binding Protein in the Macula of the Human Eye." The Journal of Biological Chemistry, vol. 279, no. 47, 2004, pp. 49447-54.
Bhosale P, Larson AJ, Frederick JM, et al. Identification and characterization of a Pi isoform of glutathione S-transferase (GSTP1) as a zeaxanthin-binding protein in the macula of the human eye. J Biol Chem. 2004;279(47):49447-54.
Bhosale, P., Larson, A. J., Frederick, J. M., Southwick, K., Thulin, C. D., & Bernstein, P. S. (2004). Identification and characterization of a Pi isoform of glutathione S-transferase (GSTP1) as a zeaxanthin-binding protein in the macula of the human eye. The Journal of Biological Chemistry, 279(47), 49447-54.
Bhosale P, et al. Identification and Characterization of a Pi Isoform of Glutathione S-transferase (GSTP1) as a Zeaxanthin-binding Protein in the Macula of the Human Eye. J Biol Chem. 2004 Nov 19;279(47):49447-54. PubMed PMID: 15355982.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Identification and characterization of a Pi isoform of glutathione S-transferase (GSTP1) as a zeaxanthin-binding protein in the macula of the human eye. AU - Bhosale,Prakash, AU - Larson,Alexander J, AU - Frederick,Jeanne M, AU - Southwick,Katie, AU - Thulin,Craig D, AU - Bernstein,Paul S, Y1 - 2004/09/07/ PY - 2004/9/10/pubmed PY - 2005/1/12/medline PY - 2004/9/10/entrez SP - 49447 EP - 54 JF - The Journal of biological chemistry JO - J. Biol. Chem. VL - 279 IS - 47 N2 - Uptake, metabolism, and stabilization of xanthophyll carotenoids in the retina are thought to be mediated by specific xanthophyll-binding proteins (XBPs). A membrane-associated XBP was purified from human macula using ion-exchange chromatography followed by gel-exclusion chromatography. Two-dimensional gel electrophoresis showed a prominent spot of 23 kDa and an isoelectric point of 5.7. Using mass spectral sequencing methods and the public NCBI database, it was identified as a Pi isoform of human glutathione S-transferase (GSTP1). Dietary (3R,3'R)-zeaxanthin displayed the highest affinity with an apparent Kd of 0.33 microm, followed by (3R,3'S-meso)-zeaxanthin with an apparent Kd of 0.52 microm. (3R,3'R,6'R)-Lutein did not display any high-affinity binding to GSTP1. Other human recombinant glutathione S-transferase (GST) proteins, GSTA1 and GSTM1, exhibited only low affinity binding of xanthophylls. (3R,3'S-meso)-Zeaxanthin, an optically inactive nondietary xanthophyll carotenoid present in the human macula, exhibited a strong induced CD spectrum in association with human macular XBP that was nearly identical to the CD spectrum induced by GSTP1. Like-wise, dietary (3R,3'R)-zeaxanthin displayed alterations in its CD spectrum in association with GSTP1 and XBP. Other mammalian xanthophyll carrier proteins such as tubulin, high-density lipoprotein, low-density lipoprotein, albumin, and beta-lactoglobulin did not bind zeaxanthins with high affinity, and they failed to induce or alter xanthophyll CD spectra to any significant extent. Immunocytochemistry with an antibody to GSTP1 on human macula sections showed highest labeling in the outer and inner plexiform layers. These results indicate that GSTP1 is a specific XBP in human macula that interacts with (3R,3'S-meso)-zeaxanthin and dietary (3R,3'R)-zeaxanthin in contrast to apparently weaker interactions with (3R,3'R,6'R)-lutein. SN - 0021-9258 UR - https://www.unboundmedicine.com/medline/citation/15355982/Identification_and_characterization_of_a_Pi_isoform_of_glutathione_S_transferase__GSTP1__as_a_zeaxanthin_binding_protein_in_the_macula_of_the_human_eye_ L2 - http://www.jbc.org/cgi/pmidlookup?view=long&pmid=15355982 DB - PRIME DP - Unbound Medicine ER -