• Food Science and Biotechnology
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• v.15 no.1
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• pp.28-32
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• 2006

Protease inhibitor of 72.6 kDa was successively purified from chum salmon (Oncorhynchus keta) eggs by ion exchange, gel permeation, and affinity chromatographies. Protease inhibitor was purified with yield and purification fold of 1.50% and 58.11, respectively. SDS-PAGE results showed purified protease inhibitor consisted of two protein subunits of 54.0 and 18.6 kDa. Chum salmon inhibitor exhibited stability between 20 and $40^{\circ}C$ in weak acid environment (PH 6), and inhibited papain and cathepsin, members of cysteine protease, but not chymotrypsin. The protein inhibited cathepsin more effectively than did egg white protease inhibitor, whereas the reverse was true for papain. These results indicate chum salmon egg inhibitor is heterodimer, thus the inhibitor was classified as cysteine protease inhibitor.

• Korean Journal of Microbiology
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• v.10 no.2
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• pp.69-72
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• 1972

The studies of neutral protease which was obtained by passing through Sephadex A-50 had been reported not long ago. Since that time the author also conducted the research to be investigated the physical properties of acid protease absorbed by Sephadex A-50. The results are summarized as follows : 1) Cultivating Aspergillus oryza SHW-131 on a wheat bran medium, the acid protease including neutral protease is very sensitive for temperature. 3) Activity of acid protease is very sensitive for temeprature. 3) This enzyme was proved, what is called, to be a sort of weak acid protease. It's optimum pH was lied in about 4.5. 4) A range of pH for stability is far more narrow than any other protease. 5) The acid protease is dropped by EDTA solution in its activity.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.2
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• pp.195-199
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• 1999

The characteristics of protease from squid viscera was investigated by response surface methodology(RSM) programmed with reaction temperature and pH. The optimal temperature and pH for the protease were 41.75$^{\circ}C$ and pH 6.02 respectively. Also its activity was 78.65 unit at the optimal condition and $R^2$ of the model was 0.8461 (P＜0.1). The protease activity was decreased by N $a^{+}$ and increased by $Mg^{2+}$ But $K^{+}$ did not affect the protease. The Km value against casein was determined to be 0.12 mM by Line-weaver-Burk plot.lot.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.2
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• pp.205-213
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• 2000

This study investigated the effect of mixing protease and lipase on detergency. The detergency of protein soiled, oil soiled and protein-oil soiled cloths and the relative hydrolytic activity of enzymes were examined. The protease-lipase added detergent solution was most effective for the removal of protein in protein-oil soiled cloths. This is because the lipase removed the protein that was physically bound to oil as well as the protease removed the protein. The protease added detergent solution was second effective, the lipase added detergent solution was third effective, and the detergent solution without protease and lipase was the least effective. The protease-lipase added detergent solution was also most effective in the oil removal from protein-oil soiled cloths. Unlike in protein removal, however, the protease added detergent solution was more effective in oil removal than the lipase added detergent solution. This is because the removal of oil bound to protein by protease was more effective than the removal of oil by lipase. In soiling-washing cycles, however, the effects of lipase increased, and as a result, the detergency of protease added detergent solution and the lipase added detergent solution became similar.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.344-351
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• 1990

An alkalophilic microoganism producing a detergent-resistant alkaline protease was isolated from soil and identified as Baeiltus sp. The alkaline protease has been partially purified by ammonium sulfate fractionation, DEAE-Cellulose, CM-Cellulose and Sephdex G-100 column chromatography. The purified alkaline protease was highly active at pH 12-13 toward casein and stable at pH values from 6 to ll. The optimum temperature for the enzyme reaction was $55^{\circ}C$. The enzyme was completely inactivated by diisopropyl fluorophosphate (DFP) indicating that the enzyme was serine protease, but considerabiy stable in the presence of surface active agents.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.667-667
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• 2000

Pseudomonas sp. BK7, an alkalophile, displayed the highest growth and protease activity when grown in a fermenter which was controlled at a pH level of 9.0, and the enzyme production was significantly enganced by the increase of agitation speed. Two formas of alkaline proteases (BK7-1 and BK7-2) were fractionated and purified to near homogeneity. Protease BK7-1 was purified through CM-Sepharose CL-6B and Sephadex G-75 column chromatographies, and Protease BK7-2 was purified through CM-Sepharose CL-6B and Sephadex G-75 column chromatographies, and Protease BK7-2 was purified through CM-Sepharose CL-6B, DEAE-Sepharose, and Sephadex G-75 column chromatographies. The molecular weights of proteases BK7-1 and BK7-2 determined by gel filtration chromatography were 20,700 and 40,800, respectively. The $K_m$ value, isoelectric point, and optimum pH of protease BK7-1 were 2.55 mg/ml, 11.0 and 11.0, respectively, whereas those of protease BK7-2 were 1.57 mg/ml, 7.2, and 10.0, respectively. Both protease were practically stable in the pH range of 5-11. The optimum temperatures for the activities of both protease BK7-1 and BK7-2 were 50℃ and 45℃, respectively. About 56% of the original protease BK7-2 activity remained after being treated at 50℃ for 30 min but protease BK7-1 was rapidly inactivated at above 25℃. Both proteases were completely inhibited by phenylmethane sulfonyl fluoride, a serine protease inhibitor. Protease BK7-2 was stable against EDTA, EGTA, STP, and detergents such as SDS and LAS, whereas protease BK7-1 was found to be unstable.

• BMB Reports
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• v.34 no.6
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• pp.509-516
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• 2001

A genomic DNA fragment that contains the gene, which codes for a novel extracellular serine protease in Burkholderia pseudomallei, was cloned by using pQE40 as a vector. It was maintained in Escherichia coli JM109. The expression of the gene(s) resulted in the production of a 52 kDa protease. The recombinant protease was purified from the culture filtrate via ammonium sulfate fractionation, gel filtration, and anion-exchange chromatography. The purified protease had an optimum pH and temperature of pH 8.9 and $38^{\circ}C$, respectively. The protease activity was inhibited by EGTA, EDTA, and PMSF, but not 1,10-phenanthroline. The first 11 amino acid residues from the N-terminus of the purified protease were identified as LAPNDPYYYGY. PNDPYY was found to show homology to the Bacillus cereus microbial serine protease and B. subtilis PD498 serine protease. These results indicate that the protease that was purified in this study is an extracellular calcium-dependent serine protease. The purified protease was able to digest the human serum 19A, IgG, albumin, and transferrin, as well as bovine muscle actin and myosin. Furthermore, it was able to promote or cause dermonecrosis in experimental rabbits. These results propose the possible role of a novel B. pseudomallei extracellular calcium-dependent serine protease in the virulence of the pathogen.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.57-63
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• 2000

To extract insoluble proteins from abolished soybean meal, the meal was treatesd with phytase and protease produced by Aspergillus sp. SM-15 and Aspergillus sp. MS-18. The extraction of insoluble soybean protein was increased at alkaline range more than pH 5 in case of phytase, pH 7 to 11 in case of protease and pH 5 to 12 in case of the mixed enzyme of phytase and protease. The optimum extraction temperature of insoluble protein was 5$0^{\circ}C$ for phytase and the mixed enzyme of phytase and protease, and 6$0^{\circ}C$ for protease. The optimum treatment time for extraction of protein was 9 hrs for phytase, 11 hrs for protease and the mixed enzyme of phytase and protease and optimum unit of enzyme for extraction of protein was 600 unit, 40 unit and 900 unit＋60 unit in case of phytase, protease, phytase and protease, respectively. The treatment of mixed enzyme showed higher extracton rate of protein than single enzyme treatment. The foaming capacity, foaming stability, emulsion capacity, and emulsion stability of soybean meal protein by the treatment of the enzymes increased at all pH range. Further more oil absorption as well as water absorption capacities by the treatment of the enzymes were also increased. The functional properteis of the soybean meal protein treated by the mixed enzyme were higher than those of soybean meal protein treated by the single enzyme.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.524-529
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• 2015

This study was conducted to optimize the medium composition for cold-adaptive protease production of Enterobacteriaceae sp. by response surface methodology (RSM). Yeast extract, and TritonX-100 were identified as the significant factors affecting protease from one-factor-at-a-time method. RSM studies for optimizing protease production of Enterobacteriaceae sp. have been carried out for three parameters including yeast extract concentration, TritonX-100 concentration, and culture pH. These significant factors were optimized as 6.690 g/L yeast extract, 0.018 g/L Triton$^{TM}$ X-10, and pH 6.677. The experimentally obtained protease activity was 8.03 U /L, and it became 1.5-fold increase before optimization.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.193-204
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• 1984

The enzymatic properties of the alkaline AL-protease, which had been prepared from the crude zymolyase of Arthrobzoter luteus, was investigated together with its active amino acid residue. Complete inactivaton of the proteolytic activity of AL-protease by either DFP or PMSF was simultaneously accompanied by the loss of its lytic effect on the lysis of yeast cell wall. In the reaction, AL-protease showed the pattern of inactivation to decrease very slowly, as compared to that of chymotrypsin, and that enzyme and DFP were found to react with a molar ratio of 1 : 1. The preparation of AL-protease exhibited no hydrolytic activity in any substrates of polysaccharases, playing a significant role in the lysis of yeast cell wall. The optimum pH and temperature of AL-protease was pH 10.5 and $65^{\circ}C$, respectively. It also showed stability in the pH range from 5 to 11 and at the temperature below $65^{\circ}C$. Through the identification of the amino acid residue in the active site of the $^{32}P$-diisopropylph-osphorylated(DIP) AL-protease modified specifically with $^{32}P$-labeled DFP, AL-protease was found to be a DFP-sensitive which has a mole of active serine residue involved in its proteolytic activity per mole of the enzyme.