NISCAIR Online Periodicals Repository

Research Journals >
Indian Journal of Biochemistry and Biophysics (IJBB) >
IJBB Vol.46 [2009] >
IJBB Vol.46(4) [August 2009] >

Title: Iron-zinc interaction during uptake in human intestinal Caco-2 cell line: Kinetic analyses and possible mechanism
Authors: Iyengar, Vasuprada
Pullakhandam, Raghu
Nair, K Madhavan
Keywords: Caco-2 cells
Issue Date: Aug-2009
Publisher: CSIR
Abstract: Iron and zinc interact at the enterocyte during absorption, but the mechanism(s) remain elusive. The aim was, therefore, to understand the mechanism of interaction using kinetic analyses of iron and zinc uptake, individually and in combination under normal and altered cellular mineral concentrations in human intestinal Caco-2 cell line. Striking differences in kinetic parameters were observed between iron and zinc uptake. Iron uptake followed a two-component model, while zinc uptake followed a three-component model. Iron uptake had a Km of 3.6 µM and Vmax of 452 pmol/mg protein/min, while zinc uptake had a Km of 42 µM and Vmax of 3.09 pmol/mg protein/min. Zinc dose-dependently inhibited iron uptake through mixed-inhibition but iron marginally increased zinc uptake. Cellular zinc repletion doubled iron uptake and eliminated inhibition, but zinc depletion decreased iron uptake. Iron pre-treatment had no effect on zinc uptake. Based on these results, a two-transporter model of iron uptake, comprising the apical iron uptake transporter divalent metal ion transporter-1 (DMT-1) and an unknown putative transporter was derived. This model for DMT-1 was verified by immunoblotting. These results implied that cellular zinc status profoundly influenced iron uptake and its interactions with zinc during uptake. DMT-1 might not simultaneously transport iron and zinc, providing a mechanistic basis for observed interactions.
Page(s): 299-306
ISSN: 0975-0959 (Online); 0301-1208 (Print)
Source:IJBB Vol.46(4) [August 2009]

Files in This Item:

File Description SizeFormat
IJBB 46(4) 299-306.pdf312.59 kBAdobe PDFView/Open
 Current Page Visits: 981 
Recommend this item


Online Submission of Articles |  NISCAIR Website |  National Knowledge Resources Consortium |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2015 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 167959 since 01-Sep-2015  Last updated on 29-Jun-2016Webmaster: