Quartz crystal microbalance with dissipation analysis of interactions between specific milk molecules and instestinal brush border membranes of importance for mammalian health
Special Symposium - Innovations in Food Technology (LMC Congress)
Innovations in Food Technology - Poster Session (LMC/Food - P1)
Keywords: helath
Dietary proteins may provide – in addition to their nutritional effects as a source of energy and essential amino acids - a wide range of biological and functional effects. Through actively communicating with the gastrointestinal (GI) tract, milk may target mammalian health beyond a supply of amino acids, carbohydrates and lipids. While some proteins, particularly caseins, contain an appropriate amino acid composition for growth and development of the developing newborn, a number of proteins and peptides encrypted in milk proteins have been shown to possess various biological effects: antimicrobial, disease resistance and to target certain nutrients and minerals to specific receptors1-3. The in vivo relevance of the identified interactions is, however, often questionable.
The quartz crystal microbalance with dissipation (QCM-D) technique is based on the piezoelectric properties of quartz. An AC voltage applied over the gold electrodes of the quartz crystal induces oscillations at a fundamental frequency and overtones thereof which can be measured. An addition of a mechanical stress occurring when matter is deposited to the quartz crystal microbalance results in a change in the resonance frequency which can be related to a deposited mass by the sauerbrey equation4. Thus, it is hypothesized that a biosensor can be prepared by depositing intestinal brush border membrane vesicles (BBMV) displaying characteristics similar to intact enterocytes5,6 to the surface of the QCM crystal. Thereby, specific components in foods interacting with BBMV, serving as a model of the small intestine, can be identified. We therefore hypothesize that specific components of milk interacting with the GI tract can be identified using the QCM-D technique combined with chromatographic and mass spectrometry methods.
In the present work, interactions between BBMV deposited on the gold surface of the quartz crystal and defatted colostrum are analyzed using the QCM-D technique. In this way, specific components contained in defatted colostrum that bind to BBMV can be identified using a novel application of the QCM-D apparatus through separation of proteins and peptides by size exclusion chromatography coupled with the quartz crystal microbalance with dissipation apparatus (LC-QCM-D).
This experimental setup will used with a simulated small intestine digestion of milk/colostrum protein components using pepsin and pancreatic protease isolates to identify whether specific proteolytic fragments bind to BBMV. In addition, proteins and peptides that have been identified with our LC-QCMD setup will be characterized using mass spectrometry. With this setup, we hope to identify novel bioactive components with potential beneficial effects on human and animal health.
1. Kawakami,H. & Lonnerdal,B. Isolation and function of a receptor for human lactoferrin in human fetal intestinal brush-border membranes. Am J Physiol Gastrointest Liver Physiol 261, G841-G846 (1991).
2. Gauthier,S.F. & Pouliot,Y. Functional and Biological Properties of Peptides Obtained by Enzymatic Hydrolysis of Whey Proteins1. J. Dairy Sci. 86, 78-87 (2003).
3. Jensen,A.R., Elnif,J., Burrin,D.G., & Sangild,P.T. Development of Intestinal Immunoglobulin Absorption and Enzyme Activities in Neonatal Pigs Is Diet Dependent. J. Nutr. 131, 3259-3265 (2001).
4. Kanazawa,K.K. & Gordon II,J.G. Frequency of a quartz microbalance in contact with liquid. Analytical Chemistry 57, 1770-1771 (1985).
5. Tosco,M., Faelli,A., Sironi,C., Gastaldi,G., & Orsenigo,M.N. A Creatine Transporter Is Operative at the Brush Border Level of the Rat Jejunal Enterocyte. Journal of Membrane Biology 202, 85-95 (2004).
6. Knopfel,M., Smith,C., & Solioz,M. ATP-driven copper transport across the intestinal brush border membrane. Biochemical and Biophysical Research Communications 330, 645-652 (2005).
Presented Wednesday 19, 13:30 to 15:00, in session Innovations in Food Technology - Poster Session (LMC/Food - P1).
