Molecular Signature of Kappa-Carrageenan Mimics Chondroitin-4-Sulfate and Dermatan Sulfate and Enables Interaction with Arylsulfatase B
journal contributionposted on 2013-11-22, 00:00 authored by Sumit Bhattacharyya, Joanne K. Tobacman
The common food additive kappa-carrageenan ( -CGN) is a sulfated polysaccharide that resembles chondroitin-4-sulfate (C4S) and dermatan sulfate (DS). All have a sulfate group on C4 of a glycoside (galactose for carrageenan and Nacetylgalactosamine for C4S), and the sulfate-bearing glycoside is linked in a -1,4- configuration to an unsulfated, 6-carbon sugar (galactose for carrageenan, glucuronate for C4S, and iduronate for DS). The enzyme arylsulfatase B (ARSB; N-acetylgalactosamine- 4-sulfate) is the highly selective enzyme that removes the 4-sulfate group from the nonreducing terminus of C4S and DS, thereby regulating subsequent degradation. In this report, -CGN is shown to be a substrate for recombinant human ARSB (rhARSB). Sulfate was generated from both C4S and -CGN following incubation with rhARSB. Exposure of human colonic epithelial cells to -CGN, but not to C4S produced reactive oxygen species (ROS) and increased Interleukin (IL)-8 secretion. The ROS production from -CGN was reduced by exposure to rhARSB, but increased by competition from C4S or DS, but not from chondroitin-6-sulfate (C6S). Prior treatment of either lambda- or iota-CGN with rhARSB had no impact on ROS, IL-8, or inorganic sulfate production, demonstrating a specific effect of the molecular configuration of -CGN. By mimicry of C4S and DS and by interaction with ARSB, -CGN can directly interfere with the normal, cellular functions of C4S, DS, and ARSB. Since C4S and DS are present in high concentration in tissues, the impact of -CGN exposure may be due to some extent by interference with the normal biological functions of ARSB, C4S, and DS.
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Publisher StatementNOTICE: This is the author’s version of a work that was accepted for publication in Journal of Nutritional Biochemistry. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Nutritional Biochemistry, Vol 23, Issue 9, (Sept. 2012) DOI:10.1016/j.jnutbio.2011.05.012