alpha-chymotrypsin and Milk-Hypersensitivity

Topics: Animals; Chymotrypsin; Food Handling; Hot Temperature; Humans; Hydrolysis; Immunoglobulin E; Infant Food; Infant, Newborn; Milk Hypersensitivity; Milk Proteins; Trypsin; Whey Proteins

Different protein sources could determine differences in the maturation of the exocrine pancreas in humans during the first months after birth; however, no studies have been carried out in man to evaluate the effect of a hydrolyzed protein diet on exopancreatic function. Our aim was therefore to determine the effect of two different milk formulas on pancreatic secretion in patients with cow's milk protein allergy (CMPA).. We selected 12 infants (median age, 3.0 months), fed for 6 weeks with a hydrolyzed casein-based formula, and 14 infants (median age, 3.0 months) who received a soy-protein based formula over the same period. As controls, two groups of age-matched infants with no gastrointestinal disease and receiving a free diet were studied. In the patients with CMPA a secretin-cerulein test was performed at the commencement of the diet and after 6 weeks; in the controls the same test was performed only once. Enzyme concentrations and outputs of trypsin, chymotrypsin, lipase, and phospholipase were assayed.. No significant difference was observed between the two groups of patients with CMPA for any of the enzymes studied, either at base line or after 6 weeks of diet. No difference was recorded between CMPA patients and age-matched controls on a free diet either. In both CMPA groups there was a significant increase over basal values in trypsin, chymotrypsin, and lipase concentrations after 6 weeks. Furthermore, there was a significant positive correlation between the age of the patients and enzyme concentrations. Mean daily weight gain was 27.4 +/- 3.9 g with hydrolyzed casein and 27.2 +/- 3.5 g in soyfed patients.. It is suggested that the diets with different protein content used in subjects with CMPA did not determine any difference in the stimulation of proteolytic and lipolytic pancreatic enzymes.

Topics: Caseins; Chymotrypsin; Female; Humans; Infant; Infant Food; Lipase; Male; Milk Hypersensitivity; Milk Proteins; Pancreas; Phospholipases; Soybean Proteins; Trypsin

Food protein allergies are a major global concern. Hydrolysis of food proteins reduces their allergenicity, but another novel approach is the covalent attachment of polysaccharides to proteins via the Maillard reaction (i.e., glycation), which blocks some IgE binding epitopes on the protein allergen. We wanted to examine whether enzymatic hydrolysis, combined with glycation, could further reduce IgE binding for people with a cow milk protein allergy. Whey protein isolate (WPI) was hydrolyzed by immobilized trypsin and chymotrypsin to degree of hydrolysis (DH) values of 17 to 27%. Immobilized enzymes were used to avoid heat-treating the hydrolysate (to inactivate the enzymes, because heating could also affect the IgE binding ability of the protein). The resultant whey protein isolate hydrolysates (WPIH) were then glycated with 10-kDa dextran (DX) in aqueous solutions held at 62°C for 24 h. We analyzed the molar mass (M

Topics: Allergens; Animals; Cattle; Child; Chymotrypsin; Dextrans; Epitopes; Female; Food Hypersensitivity; Glycosylation; Humans; Hydrolysis; Immunoglobulin E; Maillard Reaction; Milk Hypersensitivity; Protein Hydrolysates; Trypsin; Whey Proteins

Cows' milk allergy is the most frequent food allergy in children, and beta-lactoglobulin (beta-Lg) is a major allergen. Milk-based hypoallergenic ingredients are manufactured by enzymatic hydrolysis, a process that could be improved by the application of high-pressure treatments. This study showed that the treatment of beta-Lg dissolved in buffer with chymotrypsin and trypsin under high pressure for relatively short times accelerated proteolysis by leading to a rapid removal of the intact protein. The rapid proteolysis of the beta-Lg substrate under pressure led to the production, in 20 min, of hydrolysates with lower immunoglobulin (Ig) G binding than those produced in 8 h (chymotrypsin) or 48 h (trypsin) at atmospheric pressure. However, those hydrolysates retained some residual IgE-binding properties that could be traced to the preferential release, during the initial stages of proteolysis, of peptides containing IgE epitopes, such as (Val-41-Lys-60), (Leu-149-Ile-162), and (Ser-21-Arg-40). The formation of these fragments was favored when proteolysis was conducted under high pressure due to the preferential hydrolysis of Arg-40 and Arg-148 by trypsin, and Tyr-42 and Leu-149 by chymotrypsin, all located at the dimer interface of beta-Lg or very close to it. Although our results do not support that trypsin and chymotrypsin under high pressure selectively address the allergenic regions of beta-Lg, it is possible to select the conditions that quickly produce hydrolysates with reduced potential allergenicity that could be used in hypoallergenic foods.

Topics: Animals; Chromatography, High Pressure Liquid; Chymotrypsin; Epitopes; Hydrolysis; Hydrostatic Pressure; Immunoglobulin E; Lactoglobulins; Milk; Milk Hypersensitivity; Peptide Fragments; Time Factors; Trypsin