Digestibility of myofibrillar proteins by pepsin was determined by in vitro trials and mathematical modelling. A primary model was developed to predict in vitro digestion kinetics, and a secondary model based on the mechanisms of protein denaturation was then added to take into account the effect of meat heating. Model predictions agreed with measurements in the pH and pepsin concentration rang...

Amastigotes arc main pathogenic stage of I.eishmania parasite in mammalian host. During the course of leishmania infection the amastigotc surface would be covered by host proteins like immunoglobulins and complement components. These proteins produce false positive reaction and low signal/noise ratio in evaluation of antibody raising against lesion-dcrived amastigotc by indirect ELISA. 1'0 over...

BACKGROUND & OBJECTIVES Oxytocin (OT) injections to milch cattle for milk letdown have become a common practice amongst dairy farmers in India. Although there is no reported evidence, it is widely presumed that long term consumption of such milk leads to adverse health consequences. However, there is no information on the effect of exogenous OT injections on milk OT content and its stability du...

Comparison has been made of a simple method originated by Absolon and modified in our laboratories for assay of proteolytic activity using RISA (radioactive iodinated serum albumin-Abbott Laboratories), with the commonly used photometric methods of Anson and Kunitz. In this method, pepsin was incubated with an albumin substrate containing RISA, followed by precipitation of the undigested substr...

The objective of the present study was twofold: first to compare the degradation patterns of caprine whey proteins digested with either human digestive juices (gastric or duodenal) or commercial porcine enzymes (pepsin or pancreatic enzymes) and second to observe the effect of gastric pH on digestion. An in vitro two-step assay was performed at 37 degrees C to simulate digestion in the stomach ...

1. Pepsin in solution at 38 degrees C. is most stable at a hydrogen ion concentration of about 10(-5) (pH 5.0). 2. Increasing the hydrogen ion concentration above pH 5.0 causes a slow increase in the rate of destruction of pepsin. 3. Decreasing the hydrogen ion concentration below pH 5.0 causes a very rapid increase in the rate of destruction of the enzyme. 4. Neither the purity of the enzyme s...

Many sera from normal individuals as well as patients with various disease states contain agglutinating antibodies which show specificity for antigenic determinants of gamma-globulin revealed by pepsin digestion at pH 4.1. Sera containing such agglutinating activity as well as sera negative for these agglutinators contain low molecular weight (3S-5S) components of slow gamma-mobility which inhi...

A method is described for isolating a crystalline protein of high tryptic activity from beef pancreas. The protein has constant proteolytic activity and optical activity under various conditions and no indication of further fractionation could be obtained. The loss in activity corresponds to the decrease in native protein when the protein is denatured by heat, digested by pepsin, or hydrolyzed ...

The interaction between enzymes and their substrates to form intermediate complexes has long been of interest. We have found that when pepsin and egg albumin are mixed in solution at about pH 4 a precipitate forms. The influence of protein and of ion concentrations on the amount of precipitate so formed has been studied. It has been found that the precipitate dissolves at higher ionic concentra...

The aim of this study was to assess the influence of selected cardiovascular and antidiabetic drugs on in vitro pepsin activity. A total of 13 drugs were analyzed at one concentration (one tablet of drug in 50 mL of solution with deionized water). The enzyme activity was determined by the Folin method based on the reaction of tyrosine with the Folin reagent. It was found that ACE inhibitors (ap...