Identification of dietary and endogenous ileal protein losses in pigs by immunoblotting and mass spectrometry

J Nutr. 2005 May;135(5):1215-22. doi: 10.1093/jn/135.5.1215.

Abstract

Ileal flows and the endogenous or dietary origin of soluble proteins present in ileal digesta were determined in pigs fed diets containing different pea cultivars (Solara, Madria and Eiffel) and micro-ground peas (c.v. Solara). Ileal digesta proteins were analyzed by electrophoresis and densitometry analysis and were identified by LC-MS-MS spectrometry and immunoblotting. The ileal flows of proteins differed (P < 0.1) among the 3 pea cultivars; the flow in pigs fed the Madria-containing diet was higher than that of pigs fed the Eiffel- and Solara-containing diets. The flow was reduced by micro-grinding the peas. The true digestibility of pea proteins and the endogenous losses were not correlated. However, at this intestinal level, protein losses were essentially of endogenous origin (enzymes, antibodies), and from the partly digested pea albumin fraction. Pea lectin and albumin PA1b were totally resistant to gastric and small intestinal digestion and a minor resistant peptide from pea albumin PA2 was detectable. In contrast, the storage proteins, legumin and vicilin, were not detectable by antibodies or by LC-MS-MS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animal Feed
  • Animals
  • Dietary Proteins* / isolation & purification
  • Dietary Proteins* / metabolism
  • Electrophoresis
  • Ileum / physiology*
  • Immunoblotting
  • Mass Spectrometry
  • Molecular Sequence Data
  • Peptide Fragments / chemistry
  • Peptide Fragments / isolation & purification
  • Pisum sativum*
  • Plant Proteins / isolation & purification
  • Plant Proteins / metabolism
  • Proteins / isolation & purification
  • Proteins / metabolism*
  • Swine

Substances

  • Dietary Proteins
  • Peptide Fragments
  • Plant Proteins
  • Proteins