Advanced

Pigments protect the light harvesting proteins of chloroplast thylakoid membranes against digestion by gastrointestinal proteases

Emek, Sinan Cem LU ; Åkerlund, Hans-Erik LU ; Clausén, Maria LU ; Ohlsson, Lena LU ; Weström, Björn LU ; Erlanson-Albertsson, Charlotte LU and Albertsson, Per-Åke LU (2011) In Food Hydrocolloids 25(6). p.1618-1626
Abstract
Chloroplast thylakoid membranes inhibit pancreatic lipase/colipase activity in vitro and, when included in food, induce satiety signals. As thylakoid membranes themselves are nutrients, containing lipids and proteins, it is of interest to study the digestion of thylakoids by enzymes of the gastrointestinal tract. Thylakoid membranes were treated with pepsin, trypsin, gastric and pancreatic juice at 37 degrees C and the resulting enzymatic breakdown was analyzed by gel electrophoresis, electron microscopy and mass spectroscopy. In all cases, several of the proteins were degraded within half an hour, while the main parts of the pigment-protein complexes were resistant for hours. Oil emulsified thylakoids were more resistant towards the... (More)
Chloroplast thylakoid membranes inhibit pancreatic lipase/colipase activity in vitro and, when included in food, induce satiety signals. As thylakoid membranes themselves are nutrients, containing lipids and proteins, it is of interest to study the digestion of thylakoids by enzymes of the gastrointestinal tract. Thylakoid membranes were treated with pepsin, trypsin, gastric and pancreatic juice at 37 degrees C and the resulting enzymatic breakdown was analyzed by gel electrophoresis, electron microscopy and mass spectroscopy. In all cases, several of the proteins were degraded within half an hour, while the main parts of the pigment-protein complexes were resistant for hours. Oil emulsified thylakoids were more resistant towards the enzymatic breakdown. Electron microscopy demonstrated that, after treatments, the thylakoids still remained in a membrane vesicular form. The capacity of thylakoid membranes to inhibit the lipase/colipase activity was partly reduced in all cases. About 50% of the inhibition capacity remained after treatment with pancreatic juice when the thylakoids were present in an oil emulsion. Delipidated thylakoids and plasma membranes, which lack the photosynthetic pigments, were degraded rapidly by pancreatic juice. Conclusion: The pigments, closely bound to the trans-membrane helices of thylakoid membrane proteins protect these from digestion by pepsin, trypsin, gastric and pancreatic juice. This supports the notion that a substantial inhibition of lipase/colipase takes place during the first 2 h in the intestine resulting in a retardation and prolongation of lipolysis in vivo. (C) 2010 Elsevier Ltd. All rights reserved. (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
Thylakoids, Lipase, Colipase, Pepsin, Trypsin, Emulsion, Gastric and, pancreatic juice
in
Food Hydrocolloids
volume
25
issue
6
pages
1618 - 1626
publisher
Elsevier
external identifiers
  • wos:000289780200026
  • scopus:79955023399
ISSN
0268-005X
DOI
10.1016/j.foodhyd.2010.12.004
language
English
LU publication?
yes
id
3c8ad304-4755-4fe7-b5b0-4a3af9355f69 (old id 1964479)
date added to LUP
2011-05-23 14:50:17
date last changed
2017-01-01 03:47:55
@article{3c8ad304-4755-4fe7-b5b0-4a3af9355f69,
  abstract     = {Chloroplast thylakoid membranes inhibit pancreatic lipase/colipase activity in vitro and, when included in food, induce satiety signals. As thylakoid membranes themselves are nutrients, containing lipids and proteins, it is of interest to study the digestion of thylakoids by enzymes of the gastrointestinal tract. Thylakoid membranes were treated with pepsin, trypsin, gastric and pancreatic juice at 37 degrees C and the resulting enzymatic breakdown was analyzed by gel electrophoresis, electron microscopy and mass spectroscopy. In all cases, several of the proteins were degraded within half an hour, while the main parts of the pigment-protein complexes were resistant for hours. Oil emulsified thylakoids were more resistant towards the enzymatic breakdown. Electron microscopy demonstrated that, after treatments, the thylakoids still remained in a membrane vesicular form. The capacity of thylakoid membranes to inhibit the lipase/colipase activity was partly reduced in all cases. About 50% of the inhibition capacity remained after treatment with pancreatic juice when the thylakoids were present in an oil emulsion. Delipidated thylakoids and plasma membranes, which lack the photosynthetic pigments, were degraded rapidly by pancreatic juice. Conclusion: The pigments, closely bound to the trans-membrane helices of thylakoid membrane proteins protect these from digestion by pepsin, trypsin, gastric and pancreatic juice. This supports the notion that a substantial inhibition of lipase/colipase takes place during the first 2 h in the intestine resulting in a retardation and prolongation of lipolysis in vivo. (C) 2010 Elsevier Ltd. All rights reserved.},
  author       = {Emek, Sinan Cem and Åkerlund, Hans-Erik and Clausén, Maria and Ohlsson, Lena and Weström, Björn and Erlanson-Albertsson, Charlotte and Albertsson, Per-Åke},
  issn         = {0268-005X},
  keyword      = {Thylakoids,Lipase,Colipase,Pepsin,Trypsin,Emulsion,Gastric and,pancreatic juice},
  language     = {eng},
  number       = {6},
  pages        = {1618--1626},
  publisher    = {Elsevier},
  series       = {Food Hydrocolloids},
  title        = {Pigments protect the light harvesting proteins of chloroplast thylakoid membranes against digestion by gastrointestinal proteases},
  url          = {http://dx.doi.org/10.1016/j.foodhyd.2010.12.004},
  volume       = {25},
  year         = {2011},
}