• Proceedings of the Korean Society of Crop Science Conference
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• 2022.04a
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• pp.148-148
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• 2022

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.1
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• pp.88-95
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• 2011

An experiment was conducted to determine the standardized ileal digestibility (SID) of amino acids (AA) in four sources of full-fat soybeans (FFSB) and in one source of soybean meal (SBM). The FFSB had different concentrations of trypsin inhibitor units (TIU) and included two sources of conventional FFSB, and two sources of a soybean variety that was selected for a reduced concentration of the Kunitz trypsin inhibitor. The conventional FFSB was either low temperature-processed (LT-FFSB-CV; 37.7% CP, 35.4 TIU/mg) or high temperature-processed (HT-FFSB-CV; 40.5% CP, 4.4 TIU/mg). The low-Kunitz FFSB was also either low temperature-processed (LT-FFSB-LK; 36.2% CP, 23.5 TIU/mg) or high temperature-processed HT-FFSB-LK; (38.2% CP, 4.0 TIU/mg). The SBM contained 47.5% CP and 3.20 TIU/mg. Twelve weanling barrows (initial BW: $11.1{\pm}1.3\;kg$) were fitted with a T-cannula in the distal ileum. Pigs were allotted to a replicated $6{\times}6$ Latin square design with six diets and six periods per square. Five diets were prepared using each of the soybean sources as the only source of AA in the diet. An N-free diet was also included in the experiment to measure basal endogenous losses of AA. The two low temperature-processed FFSB had lower (p<0.05) AID and SID values for all indispensable AA than the two high temperature-processed FFSB and SBM. The SID values for all indispensible AA except Trp were greater (p<0.05) in LT-FFSB-LK than in LT-FFSB-CV, but the SID of AA in HT-FFSB-CV and HT-FFSB-LK were not different. The SID of AA in SBM were not different from the SID in HT-FFSB-CV and in HT-FFSB-LK. Results of this experiment show that a reduction of the TIU from 35.4 to 23.5 TIU/mg will improve the SID of AA, but this reduction is not sufficient to completely ameliorate the negative impact of trypsin inhibitors. Results also show that the SID of AA in high temperature-processed FFSB is similar to that in de-hulled SBM.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.1
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• pp.89-95
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• 1995

The efficient use as a protein source for poultry of full fat soybean (FFSB) treated under various processes, i. e. steaming under pressure 40 lbs/sq. inch for 5, 10 or 15 minutes or roasting in a baking oven at $180^{\circ}C$ for 20, 30 or 40 minutes or extruding was compared with that of soybean meal. Eight hundred straight run broiler chicks (AA 707) were randomly allotted into 8 treatments of 4 replicates, fed with, rations containing either kind of the above mentioned FFSB for 6 weeks (Wks 1-7). The protein content of the diets for chicks during 1-3, 3-6 and 6-7 weeks of age was 21, 19 and 17% respectively. The result revealed that steaming can destroy 76-92% of the trypsin inhibitor activity (TlA) in soybean, particularly that at 15 minutes, while roasting can get rid of only 13-28% TlA. Chicks fed roasted FFSB had an enlarged pancreas and showed inferior performances to the steaming and the extrusion products. Steaming should be at least 10-15 minutes in order to obtain the comparable performances to those of the extrusion or of the soybean meal. The extruded FFSB showed the best feed conversion ratio. This might be due to the very fine particle of the product.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.53-62
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• 1990

Fully grown amphibian oocytes undergo their maturation (germinal vesicle breakdown, GVBD) during in vitro follicle culture when they are stimulated with frog pituitary homogenate (FPH) or progesterone. Present experiments were designed to determine whether proteolytic enzymes are involved in the regulation of the matunation process. Treatment of a $\alpha$ -chymoiyypsin inhibitor, N a -tosyl-L-phenylalanine-chloromethyl-ketone(TP) to the oocytes exhibited a biphasic phenomenon, the induction of the maturation without added hormone at relatively low doses (0.001-1 $\mu$M) and inhibition of the hormone induced oocyte maturation at a high dose (100 $\mu$M). Treatment of a trypsin inhibitor, N a -tosyl-L-lysine-chloromethyl ketone(TLCK) to the oocytes did not induce the maturation, but rather suppressed the hormone induced oocyte maturation in a high dose(100 $\mu$ M). Treatment of exogenous iyypsin to the oocyte induced their maturation without added hormone in a dose dependent manner (0.001-1 $\mu$ M). The data presented here indicate that some proteolytic enzymes play a role in the regulation of the maturation(meiotic arrest or reinitiation) in amphibians.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.2
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• pp.119-128
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• 2013

A protease inhibitor was fractionated from fish eggs using methods based on protein solubility. Fractionation efficiency was evaluated with regard to percent recovery and total inhibitory activity (U). The fractionation of protease inhibitor (PI) from egg extracts of skipjack tuna (ST, Katsuwonus pelamis), yellowfin tuna (YT, Thunnus albacores), and Alaska pollock (AP, Theragra chalcogramma) was performed by precipitation with cold acetone or ammonium sulfate (AS). Fractions exhibiting the strongest inhibitory activity contained 20-40% (v/v) cold acetone or 40-60% saturated AS fractions. AS fractionation was more effective in isolating PI than was precipitation with acetone. The total inhibitory activity and percent recovery of fraction obtained with AS 40-60% toward trypsin and $N{\alpha}$-benzoyl-L-arginine-p-nitroanilide (BAPNA) were 4,976 U and 24.2% for ST, 3,331 U and 38.1% for YT, and 4,750 U and 43.8% for AP, respectively. In comparisons against six commercial proteases, 40-80% AS fractions, made by combining the 40-60% and 60-80% AS fractions from fish egg extract, exhibited the strongest inhibition of trypsin when using a casein substrate. These results suggest that fish eggs act as serine protease inhibitors and may be useful for protease inhibition in foodstuffs.

• The Korean Journal of Food And Nutrition
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• v.36 no.5
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• pp.415-424
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• 2023

This study investigated the nutritional characteristics of before and after fermentation of domestic soybean (Glycine max L.) by Rhizopus oligosporus. The soybean storage proteins, β-conglycinin (11S globulin) and glycinin (7S globulin), were the most abundant in Seonyu (SY) and Danbaegkong (DBK), with concentrations of 253.4 mg/g and 193.0 mg/g, respectively. For 11S/7S related to sulfur-containing amino acid, DBK had a value of 0.95, making it the most excellent nutritionally among all the cultivars. The free amino acid content significantly increased from 0.04~10.45 mg/g before fermentation to 1.37~16.95 mg/g after fermentation, and the essential amino acid composition increased, confirming an improvement in protein quality after fermentation. Phytic acid, known as a nutritional inhibitor of soybeans, decreased from 1.66~2.13 g/100 g before fermentation to 0.90~1.58 g/100 g after fermentation, suggesting that mineral absorption inhibition was alleviated. In addition, the trypsin inhibitor content is suppressed by 76.20% to 81.25% after fermentation, which is expected to improve protein utilization in the body. This study confirmed some properties of fermented products by Rhizopus oligosporus using domestic soybeans, and these results are presented to serve as the basic data for establishing new uses of Korean soybean cultivars.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.255-262
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• 1992

In vitro digestibility of filefish, protein was substantially decreased by fiber constituents in the follow-ing order : pectin (9.97%), gum karaya (7.03%), sodium alginate (6.12%),and cellulose (1.52%). The order of reduction by fibrous residues from vegetables ranked as follows : sea tangle (12.36%), Ro-maine lettuce (11.12%), perillar leaf (8.96%), and green pepper (5.15%). The inhibitory effect of the dietary fibers towards filefish protein digestion, expressed as soybean trypsin inhibitor equivalents, in-creased with added levels, but the inhibition differed with the sources of dietary fibers. Sea tangle and sodium alginate were most active in decreasing the concentration of essential amino acid from filefish protein hydrolysis. Sodium alginate exerted an inhibitory effect on the activity of trypsin, but the other fiber constituents did not have an inhibitory potency on trypsin and bacterial pretense (Streptomyces griceus). Results supported that dietary fiber components may reduce protein digestibility through the interaction of dietary fiber components with filefish protein.

• Development and Reproduction
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• v.7 no.2
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• pp.113-118
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• 2003

Follicular fluid(FF) of mammalian Graafian follicles contains various kinds of proteins and proteinases that are believed to play important roles during follicular growth oocyte maturation and ovulation of mature oocytes. Previous studies of human FF(hFF) demonstrated the presence of many serine/threonine proteinases and matrix metalloproteinases such as gelatinases, however, little is known about the caseinases. Present study was aimed to examine the presence and the property of caseinolytic enzyme in hFF. Using casein zymographic method, it was found that hFF, human adult serum and cord serum exhibited one intense 80 kDa and another weak 78 kDa bands having caseinolytic activity. When inhibitors were added to the zymographic substrate buffer, caseinolytic activity of both 80 kDa and 78 kDa proteins were inhibited by othylenediarnine tetraacetic acid(EDTA) or soybean trypsin inhibitor(SBTI), but not by E-64, phenylmethylsulfonyl fluoride(PMSF) or 1,10-phenanthroline. Thus both enzymes appear to belong to a family of trypsin-like enzyme. Addition of EDTA to the zymographic substrate buffer almost abolished the caseinolytic activity of both enzymes. However, further addition of a divalent metal ion such as CaC $l_2$, MgC $l_2$, MnC $l_2$ or ZnC $l_2$ to the same buffer fully restored the enzyme activity at 5 mM concentration despite the presence of EDTA. Based upon these observations, 80 kDa and 78 kDa caseinolytic enzymes are present in human follicular fluid and they appear to be trypsin-like enzymes of which caseinolytic activity needs the presence of $Ca^{++}$, aM $g^{++}$, M $n^{++}$ or Z $n^{++}$././././.

• Applied Biological Chemistry
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• v.41 no.8
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• pp.563-567
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• 1998

Computer aided molecular modeling can help to predict the three dimensional structure of the polypeptide without the sample. The study on soybean Bowman-Birk protease inhibitor (SBI) is valuable, because it has been recently known that SBI possesses anticarcinogenic activities and immune-stimulating properties. SBI has several isoinhibitors, whose isolation and characterization were reported in 1990. Among these, DII inhibits trypsin only. The different inhibitory specificities cannot be explained only by their different primary sequences, but is possible with further assistance by the study on their different three dimensional structures. The study on the three dimensional structure of DII using homology method is reported in this paper.

• BMB Reports
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• v.40 no.4
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• pp.604-609
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• 2007

An Asp/His catalytic site of 10-formyltetrahydrofolate dehydrogenase (FDH) was suggested to have a similar catalytic topology with the Asp/His catalytic site of serine proteases. Many studies supported the hypothesis that serine protease inhibitors can bind and modulate the activity of serine proteases by binding to the catalytic site of serine proteases. To explore the possibility that soybean trypsin inhibitor (SBTI) can recognize catalytic sites of FDH and can make a stable complex, we carried out an SBTI-affinity column by using rat liver homogenate. Surprisingly, the Rat FDH molecule with two typical liver proteins, carbamoyl-phosphate synthetase 1 (CPS1) and betaine homocysteine S-methyltransferase (BHMT) were co-purified to homogeneity on SBTI-coupled Sepharose and Sephacryl S-200 followed by Superdex 200 FPLC columns. These three liver-specific proteins make a protein complex with 300 kDa molecular mass on the gel-filtration column chromatography in vitro. Immuno-precipitation experiments by using anti-FDH and anti-SBTI antibodies also supported the fact that FDH binds to SBTI in vitro and in vivo. These results demonstrate that the catalytic site of rat FDH has a similar structure with those of serine proteases. Also, the SBTI-affinity column will be useful for the purification of rat liver proteins such as FDH, CPS1 and BHMT.