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A high-density putative monomeric mucin is the major [(35)S]labelled macromolecular product of human colorectal mucins in organ culture.

Herrmann, Annkatrin LU ; Carlstedt, Ingemar LU ; Shirazi, Tarek; Longman, Robert and Corfield, Anthony (2003) In Biochimie 85(3-4). p.381-390
Abstract
We have studied the biosynthesis of mucins in organ cultures of human colon using isopycnic density-gradient centrifugation following pulse labelling with [35S]sulphate and [3H]-D-glucosamine. A high-density [35S]sulphate labelled component, of larger size than MUC2 monomers, appeared in the tissue and also in the medium. It was not degraded by reduction, trypsin digestion, digestion with chondroitin ABC lyase or heparan sulphate III lyase, but was cleaved into smaller fragments following alkaline borohydride treatment and appears to be a monomeric, mucin-like molecule containing a protease-resistant domain with a larger hydrodynamic volume than MUC2 monomers. Although this macromolecule incorporated much more radiolabel than MUC2, it was... (More)
We have studied the biosynthesis of mucins in organ cultures of human colon using isopycnic density-gradient centrifugation following pulse labelling with [35S]sulphate and [3H]-D-glucosamine. A high-density [35S]sulphate labelled component, of larger size than MUC2 monomers, appeared in the tissue and also in the medium. It was not degraded by reduction, trypsin digestion, digestion with chondroitin ABC lyase or heparan sulphate III lyase, but was cleaved into smaller fragments following alkaline borohydride treatment and appears to be a monomeric, mucin-like molecule containing a protease-resistant domain with a larger hydrodynamic volume than MUC2 monomers. Although this macromolecule incorporated much more radiolabel than MUC2, it was not detected using chemical analysis and thus appears to be a component with a high metabolic turnover present in a very small amount. Most of the [3H]-D-glucosamine label was associated with low-density material that was well separated from MUC2, which was poorly labelled. Most of MUC2 was associated with the tissue as an ‘insoluble’ complex. The amount of MUC2 remained constant and its associated radiolabel increased only slightly with time. Analysis of the MUC2 subunits from the reduced ‘insoluble’ complex showed the typical reduction-insensitive oligomers and confirmed that the radiolabel was associated with this mucin. The large size of the [35S]-labelled putative monomeric mucin makes it difficult to separate it from reduced insoluble complex MUC2. As a result, many studies of intestinal mucin synthesis and secretion in the past have most likely been performed on ‘mixtures’ of this mucin and MUC2 and are thus not possible to interpret as the metabolic behaviour of oligomeric mucins. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Organ culture, Human colon, MUC2, Mucin
in
Biochimie
volume
85
issue
3-4
pages
381 - 390
publisher
Elsevier
external identifiers
  • wos:000183340200013
  • scopus:0038193862
ISSN
1638-6183
DOI
10.1016/S0300-9084(03)00064-6
language
English
LU publication?
yes
id
f099fea4-73cf-41db-9bf4-05a1fc9c17cc (old id 116291)
alternative location
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12770776&dopt=Abstract
date added to LUP
2007-07-12 16:07:56
date last changed
2018-01-07 06:14:40
@article{f099fea4-73cf-41db-9bf4-05a1fc9c17cc,
  abstract     = {We have studied the biosynthesis of mucins in organ cultures of human colon using isopycnic density-gradient centrifugation following pulse labelling with [35S]sulphate and [3H]-D-glucosamine. A high-density [35S]sulphate labelled component, of larger size than MUC2 monomers, appeared in the tissue and also in the medium. It was not degraded by reduction, trypsin digestion, digestion with chondroitin ABC lyase or heparan sulphate III lyase, but was cleaved into smaller fragments following alkaline borohydride treatment and appears to be a monomeric, mucin-like molecule containing a protease-resistant domain with a larger hydrodynamic volume than MUC2 monomers. Although this macromolecule incorporated much more radiolabel than MUC2, it was not detected using chemical analysis and thus appears to be a component with a high metabolic turnover present in a very small amount. Most of the [3H]-D-glucosamine label was associated with low-density material that was well separated from MUC2, which was poorly labelled. Most of MUC2 was associated with the tissue as an ‘insoluble’ complex. The amount of MUC2 remained constant and its associated radiolabel increased only slightly with time. Analysis of the MUC2 subunits from the reduced ‘insoluble’ complex showed the typical reduction-insensitive oligomers and confirmed that the radiolabel was associated with this mucin. The large size of the [35S]-labelled putative monomeric mucin makes it difficult to separate it from reduced insoluble complex MUC2. As a result, many studies of intestinal mucin synthesis and secretion in the past have most likely been performed on ‘mixtures’ of this mucin and MUC2 and are thus not possible to interpret as the metabolic behaviour of oligomeric mucins.},
  author       = {Herrmann, Annkatrin and Carlstedt, Ingemar and Shirazi, Tarek and Longman, Robert and Corfield, Anthony},
  issn         = {1638-6183},
  keyword      = {Organ culture,Human colon,MUC2,Mucin},
  language     = {eng},
  number       = {3-4},
  pages        = {381--390},
  publisher    = {Elsevier},
  series       = {Biochimie},
  title        = {A high-density putative monomeric mucin is the major [(35)S]labelled macromolecular product of human colorectal mucins in organ culture.},
  url          = {http://dx.doi.org/10.1016/S0300-9084(03)00064-6},
  volume       = {85},
  year         = {2003},
}