• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.309-319
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• 1996

Properties as related to the utilization of the crude proteases extracted from the muscle and viscera of fish (2 dark fleshed lish; anchovy, Engraulis japonica, and gizzard-shad, Clupanoda punctatus; 2 white fleshed fish; seabass, Lateolabrax japonicus, and sole, Pleuronichthys cornutus) were studied. Proteolytic activity of the muscle protease was slightly inhibited with the increase of sodium chloride concentration and it was apparent against the yellowtail myofibrillar protein than casein substrate. Proteolytic activities of the seabass and sole visceral crude protease were inhibited to 50 to $60\%\;by\;25\%$ of sodium chloride, but those of anchovy and gizzard-shad viscera crude enzymes were not influenced by sodium chloride. The vacuum freeze-dried crude protease and glycerol-mixed crude pretense of gizzard-shad and seabass muscles were almost lost their activities on the 16th week of storage, while those from the viscera of the fish were relatively stable. Degradation of the yellowtail myofibrillar protein by the anchovy muscle and viscera crude pretenses rapidly proceeded in the beginning of the reaction and the degraded products were mainly distributed in the range of 6 to 15 kDa electrophoretically.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.404-408
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• 1997

Enzymatically hydrolyzed vegetable protein (eHVP) was produced from soy protein using proteases, and the physicochemical properties were examined. Soy protein hydrolysate of 6% protein and 50% degree of hydrolysis was useful for the base of savory ingredients. The Maillard-reacted and flavoring compound-added hydrolysate had improved flavor. It was for enzymatically hydrolyzed soy sauces and dehydrated seasonings. ISP hydrolysate of low molecular weight $(MW{\sim}250)$ and high protein content (85%) was suitable for special uses such as infant diets, sports nutrition, and medical diets. The eHVP gave no limitation of dosage in the formulation as a flavor enhancer. The byproduct of protein hydrolysis was found to have high content of fiber (21%) and to have potential for the use as dietary fiber or bulking agents.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.550-555
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• 2008

An efficient production method of spirulina extract was developed by enzymatic treatment using proteolytic enzymes. The suitable dosage of Tunicase, a cell lytic enzyme, was used to be 2.0% (w/w). To maximize solid recovery and spirulina extraction (SE) index, which indicates nucleic acid-related substances content, the dosage of Alcalase, commercially available pretense, was found to be 1.0% (w/w). By simultaneous treatments using optimal dosages of Tunicase and Alcalase, the highest SE index and solid recovery were obtained. The SE index and solid recovery of simultaneous treatments were notably enhanced by 100% ($11.4%\;{\rightarrow}\;22.8%$) and 56% ($45.2%\;{\rightarrow}\;70.7%$), respectively, than those of the non-treated extracts.

• Parasites, Hosts and Diseases
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• v.33 no.3
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• pp.211-218
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• 1995

To clarify the correlation of the proteinase activity with pathogenicity of Clonorrhis sinensis, the proteinase activity either in excretory-secretory products (ESP) or in crude extracts of adult C. sinensis was examined. Substrate gel electrophoresis of the ESP and crude extracts revealed four distinct enzyme bands, which were differently inhibited by the specific proteinase inhibitors. The proteinase of the ESP with molecular mass of 24 kDa, was purified 23-fold with 14.5% yield by spectra gel ACA 44 gel filtration. It exhibited optimal pH at 7.5 in sodium phosphate (0.1 M). Its activity was inhibited specifically by N-ethylmaleimide (NEMI and antipain whereas potentiated 1.9 folds in the presence of 5 mM dithiothreitol (DTT). Cytotoxicity of the proteinase increased in a dose- dependent manner up to 120 ㎍/ml while reduced by NEM and antipain, indicating that cysteine proteinase was responsible for the cytotoxicity. This result shows that the 24 kDa cysteine proteinase is deeply correlated with the pathogenicity of C. sinensis infection.

• KSBB Journal
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• v.10 no.5
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• pp.510-517
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• 1995

The hydrolysates of three kinds [FSEH(first step enzymatic hydrolysate), SSEH(second step enzymatic hydrolysate), and TSEH(third step enzymatic hydyolysate)] were prepared by continuous hydrolysis of Alaska pollack(Theragra chalcogramma) skin gelatin with three-step membrane enzyme reactor. The molecular weight distributions of FSEH, SSEH, and THSE are 9,500∼4,800Da, 6,600∼3,400Da, and 2,300∼900Da, respectively. The contents of amino acid having sweet taste (glycine, proline, serine, alanine, hydroxyproline, glutamic acid, and aspartic acid) were about 70% of total amino acid being in the three kind hydrolysates. We also tried preparing of natural seasonings (complex seasoning and enzymeatic hydrolysale sauce) using the hydrolysates. From the results of sensory evaluations, complex seasoning containing TSEH was nearly equal to shellfish complex seasoning on the market. The mixture sauce which was made by mixing of 80% enzymatic hydrolysis sauce and 20% fermented soy sauce, was at least similar to the tradition soybean sauce in product quality, too.

• Parasites, Hosts and Diseases
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• v.36 no.2
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• pp.133-142
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• 1998

A 40 kDa cysteine protease was purified from the crude extract of adult worms of GMnnophalloines seoi by two consecutive steps: Sephacryl S-200 HR and DEAE- Sephacel chromatography. Enzyme activities were completely inhibited by cysteine protease inhibitors, L-lorans-epoxysuccinylleucylamido (4-guanidino) butane (E-64) and iodoacetic acid, strongly suggesting that the purified enzyme belongs to the cysteine family of proteases. The enzyme was maximally acive at pH 4.5 in 0.1 M of buffer, and its activity was greatly potentiated in the presence of 5 mM dithiothreitol. The protease degraded macromolecules with differential capabilities : it degraded extracellular matrix proteins, such as collagen and fibronectin, with a stronger activity against collagen than fibronectin . However, the enzyme digested hemoglobin and human immunoglobulins only slightly. leaving them nearly intact after an overnight reaction. Our results suggest that the cysteine protease of G. seoi adults is potentially significant in the nutrient uptake from the host intestine.

• Journal of Adhesion and Interface
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• v.7 no.2
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• pp.19-25
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• 2006

Since the enzymatic degradation of microbial poly(hydroxylalkanoate)s (PHAs), such as poly[(R)-3-hydroxybutyrate] and poly[(R)-3-hydroxybutyrate-co-3-hydroxyvalerate] initially occurs by a surface erosion process, their degradation behaviors can be controlled by the change of surface property. In order to control the rate of enzymatic degradation, plasma modification technique was applied to change the surface property of microbial PHAs. The surface hydrophobic and hydrophilic properties of PHA films were introduced by $CF_3H$ and $O_2$ plasma exposures, respectively. The enzymatic degradation was carried out at $37^{\circ}C$ in 0.1 M potassium phosphate buffer (pH 7.4) in the presence of an extracellular PHB depolymerase purified from Alcaligenes facalis T1. The results showed that the significant retardation of initial enzymatic erosion of $CF_3H$ plasma-treated PHAs was observed due to the hydrophobicity and the enzyme inactivity of the fluorinated surface layers while the erosion rate of $O_2$ plasma-treated PHAs was not accelerated.

• Journal of fish pathology
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• v.27 no.1
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• pp.25-33
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• 2014

Hydrolase activities of excretory-secretory products (ESP) and somatic extracts (SE) from Anisakis simplex sensu stricto (s.s.) and Anisakis pegreffii larvae were investigated by using API ZYM kit. In esterase group, acid phosphatase showed high activity from both of A. simplex (s.s.) and A. pegreffii. Esterase (C4) showed activity only from SE and A. simplex (s.s.) showed higher activity than A. pegreffii. Alkaline phosphatase, acid phosphatase and naphthol-AS-BI-phosphohydrolase showed higher activity in 3rd stage larvae than in 4th stage larvae of both species. In aminopeptidase group, only leucine arylamidase showed remarkable activity in SE of both anisakid species, and A. simplex (s.s.) SE showed higher activity than A. pegreffii SE. In glycosidase group, N-acetyl-${\beta}$-glucosaminidase, ${\alpha}$-mannosidase, ${\alpha}$-fucosidase showed higher activity in A. simplex (s.s.) than A. pegreffii, and 4th larvae showed higher activity than 3rd larvae. These differences in hydrolase activity of anisakid nematodes larvae are thought to be due to different metabolism such as growth, moulting, digestion and feeding.

• Parasites, Hosts and Diseases
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• v.31 no.2
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• pp.117-128
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• 1993

Ten axonic isolates of Trichomonns uaginolis were subcutaneously injected to the BALB/c mice in order to assess their pathogenicity by means of so-called "mouse assay" method. All the isolates revealed neutral and acid proteinase activities both in their Iysates and in culture media, but the specific activities of both proteinases in the severely pathogenic group were significantly higher than the mildly pathogenic group (p < 0.05). In the SDS-PAGE system in which the electrophoretic gels contained 0.4% gelatin as the substrate, five different handing patterns of trichomonal proteinases were detected, and the patterns were closely related with the pathogenicity of the isolates of T. vosinalis. All five bands might be regarded as cysteine proteinases group in the inhibitor assays. The cytotoxicity of the Iysates of T. vaginalis to the target Chinese hamster ovarian (CHO) cell line was also significantly different according to the pathogenicity of the isolates, and generally lower in the Iysates treated with cysteine proteinase inhibitors than in the control Iysates. In summarizing the results, it might be considered that the proteinases of T.vaginalis showing five electrophoretic banding patterns are closely related with the pathogenicity and cytotoxicity of the isolates of T. voginolis.

• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.265-270
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• 2017

A key virulence factor for urinary tract pathogens is the enzyme urease, which catalyzes the hydrolysis of urea into ammonium ions and carbonic acid. Urease activity plays an important role in the pathogenesis of urinary tract infection. In this study, the inhibitory effect of zerumbone against six urease-producing bacteria (Klebsiella oxytoca, K. pneumoniae, Morganella morganii, Proteus mirabilis, P. vulgaris, and Staphylococcus saprophyticus) and their urease activities were evaluated. The results of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests showed that zerumbone had antibacterial effect against these six urease-producing bacteria. The MIC and MBC of zerumbone ranged from 0.5 to 2 mM and 1 to 4 mM, respectively. In the urease inhibitory assay, zerumbone showed better urease inhibition ($56.28{\pm}2.45-37.83{\pm}3.47%$) than the standard urease inhibitor, acetohydroxamic acid ($40.46{\pm}1.94-22.99{\pm}3.53%$). However, zerumbone did not affect the levels of the urease subunit. These results clearly indicated that zerumbone has antibacterial potential against urease-producing bacteria and possesses excellent bacterial urease inhibition properties.