• Journal of Nutrition and Health
• /
• v.4 no.4
• /
• pp.25-28
• /
• 1971

The effects of additives for food and drug upon the tryptic hydrolysis of casein an a Synthetic substrate, $N^{\alpha}-Benzoyl-L-arginine$ ethylester (BAEE) in vitro has been studied. The results of this study were summarized as follows 1) It was found that the action of inhibition became stronger in the following order: Methyl parabene>Rose Bengal> Phloxine> Sod. DHA> Erythrosine by the colorimetric method using BAEE. These results also showed that other additives had no effect on the activity of trypsin. 2) All samples tested showed respectively same tendency using casein in this method. But the activity by Erythrosine and Sod. DHA was slightly increased in this experiment.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.4 no.1
• /
• pp.49-53
• /
• 1975

The effect of natural condiments on peptic hydrolysis of casein in vitro has been studied, peptic activity was determined by the colorimetric method using folin reagent. The obstructive compounds on colorimetry from hydrolyzates of casein were separated by gel filteration method using sephadex G-10 column and 0.05M NaCl. Zinger and red pepper $(0.1{\sim}1.0%)$ were found to have slightly supressing effect for protein digestive action of pepsin. But garlic, green onion and onion acted as synergist for protein digertive action of pepsin.

• The Journal of Korean Medicine
• /
• v.27 no.2 s.66
• /
• pp.103-110
• /
• 2006

Objectives : This study was conducted to investigate the effects of ginseng saponins and commercial surfactants such as Triton X-100, sodium deoxycholate, and sodium dodecyl sulfate on the gastric enzyme-catalyzed hydrolysis. Methods : Saponins (a surface-active plant component) from fresh ginseng root were extracted to examine its effect on the gastric enzyme-catalyzed hydrolysis. Commercial surfactants such as Triton X-100, sodium deoxycholate, and sodium dodecyl sulfate were also employed in the hydrolysis system to compare their effects with that of the ginseng saponins. The effects of surfactants on the gastric enzyme-catalyzed hydrolysis were measured by using a spectrophotometer. A spectropolarimeter was used to examine the conformational change of enzymes and substrates by the addition of ginseng saponins into the system. Results : Both the tryptic and the peptic digestion of milk casein or eggalbumin were slightly improved with an increase in the amount of ginseng saponins in the system. Triton X-100 showed an effect similar to that of ginseng saponins, while sodium dodecyl sulfate and sodium deoxycholate diminished the hydrolysis. Circular dichroism spectra of enzymes and substrates was significantly changed by the addition of ginseng saponins into the system. Conclusions : These results show that ginseng saponins affect positively the gastric enzyme-catalyzed hydrolysis, and suggest that the digestion of substrates by gastric enzymes is affected by the change of enzyme conformation by ginseng saponins.

• Journal of Animal Science and Technology
• /
• v.44 no.6
• /
• pp.801-808
• /
• 2002

Proteolytic activities of some commercial milk clotting enzymes(rennet, trypsin, pepsin, papain W-40, neutrase 1.5 and protease S) in bovine skim milk containing 0.02% $CaCl_2$ were determined by measuring DH(Degree of Hydrolysis), NPN(Non Protein Nitrogen) and by comparing patterns of SDS-PAGE(Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis). The DH of microbial enzymes(neutrase 1.5 and protease S) and trypsin in bovine skim milk were higher than those of pepsin and papain W-40. The amounts of NPN in the milk treated with trypsin and the other animal enzymes(rennet and pepsin) showed the highest and lowest degrees of proteolysis, respectively. SDS-PAGE showed that trypsin and protease S hydrolyzed $\alpha$-lactalbumin and papain W-40 hydrolyzed $\beta$-lactoglobulin slightly, while neutrase 1.5 hydrolyzed both $\alpha$-lactalbumin and $\beta$-lactoglobulin after treating for 90 min. Trypsin and protease S easily hydrolyzed ${\alpha}_s$-casein and $\beta$-casein, which were not hydrolyzed by rennet. Papain W-40 hydrolyzed $\kappa$-casein more than rennet as shown in SDS-PAGE. Based on the results of the experiments, the DH and NPN of trypsin, neutrase 1.5 and protease S were shown to be higher than those of the other enzymes. The SDS-PAGE patterns of papain W-40 and neutrase 1.5 were similar with that of rennet.

• Journal of Dairy Science and Biotechnology
• /
• v.31 no.1
• /
• pp.67-73
• /
• 2013

Food allergy is defined as adverse reactions toward food mediated by aberrant immune mechanisms. Cow's milk allergy is one of the most common food allergies in childhood. This allergy is normally outgrown in the first year of life, however 15% of allergic children remain allergic. Cow's milk allergy seem to be associated with casein (${\alpha}_{s1}$-CN), ${\beta}$-lactoglobulin and whey protein. In addition to this, many other milk proteins are antigenic and capable of inducing immune responses. Various food processing affects the stability, structure and intermolecular interactions of cow milk proteins, as a result reduction the allergenic capacity. Heating, hydrolysis, chemical, proteolytic and other processes such as gamma-ray irradiation, high pressure, using probiotics treatments of milk to obtain hypoallergenic milk have been developed to reduce allergic reactions.

• Microbiology and Biotechnology Letters
• /
• v.21 no.1
• /
• pp.30-35
• /
• 1993

Clp is a relatively abundant ATP-dependent protease found in E. coli. Its specific activity was proportional to the concentration of the limiting amount of Clp A and an excess amount of Clp P, and vice versa. Clp A has an intrinsic ATPase activity that is stimulated by casein, and contains a second site for binding A TP, in addition to the ATPase site. The modification of sulfhydryl groups in Clp A with reagents which have bulky groups such as N-phenylmaleimide led to nullifying both ATPase and protease activity. The same sites were modified by sulfhydryl reagents. It seems that the sulfhydryl groups of Clp A are not directly involved in catalysis. Since non-hydrolyzable analogs of ATP do not activate Clp, ATP hydrolysis may be essential for the proteolytic activity of Clp protease. Clp A and Clp P did not associate in the absence of nucleotide. The results suggest that the activity of the proteolytic component, Clp P, is regulated by the A TP-dependent cycling of Clp A between the activator form and the non-activator form.

• Preventive Nutrition and Food Science
• /
• v.7 no.1
• /
• pp.43-47
• /
• 2002

Crude caseinomacropeptide (CMP) was prepared from Na-caseinate using a commercial renneting enzyme. Most of the crude CMP was released from the Na-caseinate by hydrolyzing with the enzyme for 40 min. The hydrolysis of the k-casein with carbohydrate was slower than that of the k-casein without carbohydrate, as shown by the analyses of the sialic acid content and the tricine-SDS-polyacrylamide gel electrophoresis. The yield of crude CMP from Na-caseinate was 3.7%. Cation exchange chromatography showed that the crude CMP consisted of 40.5% CMP and 59.5% caseinogylcomacropetide (CGP). The effect of the TCA concentration on the solubility of CMP and CGP was determined by using crude CMP. The amounts of crude CMP and sialic acid decreased in the proportion to the increase of trichloroacetic acid (TCA) concentration from 2 to 12%, suggesting that the CGP containing carbohydrate, as well as the CMP having no carbohydrate, was precipitated in a range of 4 to 12%, depending on the TCA concentration. This result supports the hypothesis that the different non-glycosylated and glycosylated forms of CMP have different sensitivities to TCA precipitation.

• Journal of Life Science
• /
• v.8 no.6
• /
• pp.627-637
• /
• 1998

In order to utilize tuna pyloric caeca among fish intestines wasted when treated raw fish in fish processing manufactory, a crude enzyme with high proteolytic activity was extracted and its optimum condition were investigated. An immobilized enzymes also were prepared by adsorption method to enhance thermostability of the crude proteinase. The yield of the crude proteinase was approximately 2.7% on dry basis. The proteolytic activity for casein was 0.54 U/mg protein, for BTEE 1.10 U/mg protein, and for BAEE 2.69 U/mg protein. It was almost similar to that of the commercial trypsin purified. Optimum hydrolysis activity of the crude proteinase was about 80%, as the degree of hydrolysis for casein, at pH 10.0 and 45$^{\circ}C$ for 12 hrs. Also, when the crude proteinase was immobilized on DEAE-Cellulose and chitin, the residual activities remained after 7 days of pre-incubation time were maintained about 90% or more and their thermostabilities were enhanced by about 50%, compared with the native enzyme.

• Plant Resources
• /
• v.2 no.2
• /
• pp.81-87
• /
• 1999

Sixteen isolates showing relatively strong antagonicity against the ginger rhizome rot pathogen, Pythium zingiberum, were selected among the 155 isolates from ginger rhizome surfaces and rhizospheres of ginger cultivation fields in Wanju, Chonbuk. The isolate, 'HB 26-5'showing the strongest antagonicity was finally selected by testing duration of inhibition effect and pathogenicity to ginger. The isolated antagonistic microorganism, 'HB 26-5' was rod shape, gram positive and formed endospore. The isolate produced acids utilizing glucose, arabinose, xylose and mannitol, and acetoin at VP test, and grew anaerobically. Temperature range for growth was from 10 to 4$0^{\circ}C$ . Reaction to catalase and gelatin, hydrolysis were positive, and casein hydrolysis and indol production were negative. Based on the mycological characters and the fatty acid composition, it was identified as Bacillus polymyxa. The pathogenicity test of isolated Bacillus polymyxa 'HB 26-5'on 22 crop cultivars resulted that only the lettuce was influenced in germination, and the others were not affected.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.2
• /
• pp.135-143
• /
• 2014

Exopeptidase active fractions from the hepatopancreas of the Argentina shortfin squid Illex argentinus, were obtained with acetone (AC 30-40%), ammonium sulfate (AS 60-70% saturation), anion exchange chromatography (AE-II, 0.2 M NaCl) and gel filtration chromatography (GF-I, 30-50 kDa) fractionation methods. A bitter peptide solution that has a bitterness equivalent to that of 2% glycylphenylalanine and prepared by tryptic hydrolysis of milk casein, was treated with the exopeptidase active fractions. The GF-I fraction was the best based on aminopeptidase activity (35.3 U/mg), percentage of recovery (30.7%) and a sensory evaluation (1.7). The amount of released amino acids increased as incubation time increased, and the bitterness of the enzyme reaction mixtures decreased. Incubation with the GF-I fraction for 24 h resulted in the hydrolysis of several peptides as revealed by the reverse-phase high performance liguid chromatography profile, with three peaks (3, 5 and 6) decreasing in area (%) and three peaks (1, 2 and 4) increasing in area (%). Therefore, the GF-I fraction appeared to be ideally suited to reduce bitterness in protein hydrolysates by catalyzing the hydrolysis of bitter peptides.