Mineral-Binding Proteins and Peptides and Bioavailability of Trace Elements

2005 ◽  
pp. 41-67 ◽  
Author(s):  
S Bouhallab ◽  
D Bouglé
Keyword(s):  
Trace Elements ◽  
Binding Proteins ◽  
Mineral Binding ◽  
Proteins And Peptides

scholarly journals Antibacterial properties of the sperm-binding proteins and peptides of human epididymis 2 (HE2) family; salt sensitivity, structural dependence and their interaction with outer and cytoplasmic membranes of Escherichia coli

2003 ◽  
Vol 372 (2) ◽  
pp. 473-483 ◽  
Author(s):  
Suresh YENUGU ◽  
Katherine G. HAMIL ◽  
Charles E. BIRSE ◽  
Steven M. RUBEN ◽  
Frank S. FRENCH ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Binding Proteins ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Full Length ◽  
Duration Of Treatment ◽  
Human Epididymis ◽  
Sperm Binding ◽  
Proteins And Peptides

During passage through the epididymis, sperm interact with secreted epididymal proteins that promote maturation, including the acquisition of motility and fertilization competence. Viewed previously as distinct from sperm maturation, host defence capabilities are now recognized functions of the human epididymis 2 (HE2) family of sperm-binding proteins. We analysed the potent dose and time-dependent bactericidal activity of recombinant HE2α, HE2β1 and HE2β2 and found that the full-length proteins (10 μg/ml or ~1 μM) caused more than a 50% decrease in Escherichia coli colony forming units within 15 min. By contrast, human β-defensin-1, at a similar concentration, required more than 90 min to exhibit similar antibacterial activity. The epididymis-specific lipocalin, LCN6, failed to kill bacteria. Higher concentrations (25–100 μg/ml) of HE2 proteins and a longer duration of treatment resulted in near total inhibition of bacterial growth. The C-terminal peptides of HE2α, HEβ1 and HEβ2 proteins exhibited antibacterial activity similar to their full-length counterparts, indicating that the antibacterial activity of HE2 proteins resides in these C-terminal regions. Antibacterial activities of HE2 proteins and peptides were slightly inhibited by NaCl concentrations of up to 150 mM, while human β-defensin-1 activity was nearly eliminated. Reduction and alkylation of disulphide bonds in HE2 proteins and their C-terminal peptides abolished their antibacterial activity. Consistent with the ability to kill bacteria, full-length HE2 proteins and C-terminal peptides caused rapid dose-dependent permeabilization of outer and cytoplasmic E. coli membranes. A much longer exposure time was required for human β-defensin-1-mediated permeabilization of membranes, suggesting a possible difference in mode of action compared with the HE2 antibacterial peptides.

Role of metal-binding proteins and peptides in bioremediation of toxic metals

2021 ◽  
pp. 437-444
Author(s):  
Mahmood-ur -Rahman ◽  
Hafiza Sania Khalid ◽  
Muhammad Farhan Akhtar ◽  
Munazza Ijaz ◽  
Muhammad Iqbal ◽  
...  
Keyword(s):  
Toxic Metals ◽  
Metal Binding ◽  
Binding Proteins ◽  
Proteins And Peptides

scholarly journals Use of α-Lactalbumin [α-La] from Whey as a Vehicle for Bioactive Compounds in Food Technology and Pharmaceutics: A Review

2021 ◽  
Vol 03 (02) ◽  
pp. 1-1
Author(s):  
Andrea P. Cuevas-Gómez ◽  
◽  
Izlia J. Arroyo-Maya ◽  
Humberto Hernández-Sánchez ◽  
◽  
...  
Keyword(s):  
Whey Protein ◽  
Food Industry ◽  
Membrane Separation ◽  
Gel Filtration ◽  
Filtration Membrane ◽  
Production Technologies ◽  
Pharmaceutical Industries ◽  
Mineral Binding ◽  
Whey Protein Isolates ◽  
Proteins And Peptides

Whey protein is a byproduct of cheese, casein, and Greek yogurt produced in Europe, North America, and Australasia. It is a substantial source of functional proteins and peptides for the worldwide food industry. α-Lactalbumin (α-La) is a globular protein that can be isolated from WPI (whey protein isolates) using techniques such as chromatography/gel filtration, membrane separation, etc. α-La is used in the elaboration of functional foods and is a very good source of peptides with anticancer, antimicrobial, antiviral, antihypertensive, immunomodulating, opioid, mineral-binding, and antioxidant bioactivities. Nanotubes and nanoparticles generated from this protein are utilized as vehicles for the transport of active compounds, and thus, can be used in foods and pharmaceutical industries. The contaminant effects of whey, characteristics of α-La, production technologies, and its applications in nanotechnology are reviewed here.

Bioactive Proteins and Peptides in Foods

2011 ◽  
Vol 81 (23) ◽  
pp. 181-192 ◽  
Author(s):  
Barbara Walther ◽  
Robert Sieber
Keyword(s):  
Gastrointestinal Tract ◽  
Bioactive Peptides ◽  
Proteolytic Enzymes ◽  
Biological Activities ◽  
Health Claims ◽  
Biological Functions ◽  
Food Proteins ◽  
Bioactive Proteins ◽  
Mineral Binding ◽  
Proteins And Peptides

Increasing amounts of data demonstrate a bioactive role of proteins and peptides above and beyond their nutritional impact. The focus of the investigations has mainly been on vitamin- and mineral-binding proteins, on antimicrobial, immunosuppressing/-modulatory proteins, and on proteins with enzyme inhibitory activity as well as on hormones and growth factors from different food proteins; most research has been performed on milk proteins. Because of their molecular size, intact absorption of proteins in the human gastrointestinal tract is limited. Therefore, most of the proteins with biological functions show physiological activity in the gastrointestinal tract by enhancing nutrient absorption, inhibiting enzymes, and modulating the immune system to defend against pathogens. Peptides are released during fermentation or digestion from food proteins by proteolytic enzymes; such peptides have been found mainly in milk. Some of these released peptides exert biological activities such as opiate-like, antihypertensive, mineral-binding, antioxidative, antimicrobial, immuno-, and cytomodulating activity. Intact absorption of these smaller peptides is more likely than that of the larger proteins. Consequently, other organs than the gastrointestinal tract are possible targets for their biological functions. Bioactive proteins as well as bioactive peptides are part of a balanced diet. It is possible to accumulate bioactive peptides in food, for example by using specific microorganisms in fermented dairy products. Although bioactive peptides have been the subject of several studies in vitro and in vivo, their health potential is still under investigation. Up to now, the Commission of European Communities has not (yet) authorized any health claims for bioactive proteins and peptides from food.

scholarly journals Mineral-binding milk proteins and peptides; occurrence, biochemical and technological characteristics

2000 ◽  
Vol 84 (S1) ◽  
pp. 91-98 ◽  
Author(s):  
Gerd E. Vegarud ◽  
T. Langsrud ◽  
C. Svenning
Keyword(s):  
Trace Elements ◽  
Specific Binding ◽  
Whey Proteins ◽  
Milk Proteins ◽  
Inorganic Ions ◽  
Specific Binding Sites ◽  
Long Time ◽  
Proteins And Peptides

Minerals and trace elements in cow's milk occur as inorganic ions and salts or form complexes with proteins and peptides, carbohydrates, fats and small molecules. The main mineral binder or chelators of calcium are the caseins, αs1-casein, αs2-casein, β-casein and κ-casein, but also whey proteins and lactoferrin bind specific minerals like calcium, magnesium, zinc, iron, sodium and potassium. Less documented is the binding of trace elements. Peptides obtained byin vitroorin vivohydrolysis act as mineral trappers through specific and non-specific binding sites. They may then function as carriers, chelators, of various minerals and thus enhance or inhibit bioavailability. Peptides from milk proteins have found interesting new applications in the food industry as products with improved functionality or as ingredients of dietary products, or used in pharmaceutical industry. Fortification of foods with minerals in a low concentration has for a long time been used in some countries to overcome mineral deficiency, which is an increasing problem in humans. These types of foods are being used to create a new generation of super foods in the industry today.

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