• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3571-3575
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• 2014

Proteasome, a multicatalytic protease complex, has been validated as a promising therapeutic target in oncology. Carfilzomib (Kyprolis$^{(R)}$), a tetrapeptide epoxyketone, irreversibly inhibits the chymotrypsin-like (CT-L) activity of the proteasome and has been recently approved for multiple myeloma treatment by FDA. A chemistry effort was initiated to discover the compounds that are reversibly inhibit the proteasome by replacing the epoxyketone moiety of carfilzomib with a variety of ketones as reversible and covalent warheads at the C-terminus. The newly synthesized compounds exhibited significant inhibitory activity against CT-L activity of the human 20S proteasome. When the compounds were tested for cancer cell viability, 14-8 was found to be most potent in inhibiting Molt-4 acute lymphoblastic leukemia cell line with a $GI_{50}$ of $4.4{\mu}M$. Cytotoxic effects of 14-8 were further evaluated by cell cycle analysis and Western blotting, demonstrating activation of apoptotic pathways.

• 한국작물학회지
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• 제49권4호
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• pp.342-348
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• 2004

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the $60\%$ isopropanol extract of soybean(Glycine max [L.] Merr.) seed revealed two abundant proteins with molecular masses of 19 and 10 kDa. Amino acid analysis revealed that the isopropanol-extractable protein fraction was rich in cysteine. Two-dimensional gel electro-phoretic analysis indicated that the 19kDa and 10kDa proteins had pI of 4.2 and 4.0 respectively. Peptide mass fingerprints of trypsin digests of the two proteins obtained using matrix-assisted, laser desorption/ionization-time of flight (MALDI-TOF) mass spectroscopy revealed the 19kDa protein was Kunitz trypsin inhibitor and the 10kDa protein was Bowman-Birk proteinase inhibitor. When resolved under non-denaturing conditions, the isopropanol-extracted proteins inhibited trypsin and chymotrypsin activity. Results presented in this study demonstrate that isopropanol extraction of soybean seed could be used as a simple and rapid method to obtain a protein fraction enriched in Kunitz trypsin and Bowman-Birk proteinase inhibitors. Since proteinase inhibitors are rich in sulfur amino acids and are putative anticarcinogens, this rapid and inexpensive isolation procedure could facilitate efforts in nutrition and cancer research.

• 한국축산식품학회지
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• 제30권5호
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• pp.795-803
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• 2010

A DF01 strain that inhibits tyramine-producing Lactobacillus curvatus KFRI 166 was isolated from Dongchimi, a traditional Korean fermented vegetable, and identified as Lactobacillus brevis by biochemical analysis and reverse transcriptase sequencing of 16S rRNA. The antimicrobial compound produced by L. brevis DF01 was secreted at a maximum level of 640 AU/mL in late exponential phase in MRS broth, and its activity remained constant during stationary phase. The activity of bacteriocin DF01 was totally inactivated by $\alpha$-chymotrypsin, pronase E, proteinase K, trypsin, and $\alpha$-amylase, but not by catalase, which indicates the compound was glycoprotein in nature. The activity was not affected by pH changes ranging from 2 to 12 or heat treatment (60, 80, and $100^{\circ}C$ for 30 min), but was reduced after autoclaving. Bacteriocin DF01 had bacteriolytic activity and a molecular weight of approximately 8.2 kDa, as shown by tricine-SDS-PAGE analysis. Therefore, bacteriocin DF01 can be used in the manufacture of fermented meat products due to its inhibition of tyramine-producing L. curvatus and non-inhibition of L. sake, which is used as a starter culture for meat fermentation.

• Asian-Australasian Journal of Animal Sciences
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• 제13권8호
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• pp.1044-1049
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• 2000

Three wethers fitted with silastic catheters for collection of pancreatic juice, and cannulas located in the abomasum and the duodenum were used to investigate the effects of different hay and energy intake on pancreatic exocrine secretion. The wethers were fed Italian ryegrass hay or alfalfa hay at maintenance energy requirement and alfalfa hay ad libitum. High energy intake from alfalfa significantly increased abomasal flow of dry matter and both the concentration and daily secretion of ${\alpha}-amylase $. The high energy intake also tended to increase daily secretion of lipase, trypsin and chymotrypsin through the large volume of pancreatic juice. Compared with Italian ryegrass hay, alfalfa hay at the maintenance decreased abomasal dry matter flow, but increased concentration of ${\alpha}-amylase $ in the pancreatic juice, and tended to increase daily secretion of ${\alpha}-amylase $. The secretion of the other enzymes was not different between the two hays at maintenance intake. These results suggest that the kind of hay could change the concentration of ${\alpha}-amylase $ in the pancreatic juice, and that the intake level of alfalfa hay affects the ${\alpha}-amylase $ concentration and the juice volume secreted from the pancreas.

• 한국수산과학회지
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• 제44권5호
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• pp.456-463
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• 2011

We attempted to isolate a collagenase-1 inhibitory peptide from skate Dipturus chilensis skin protein. The protein from skate skin was digested by various enzymes (alcalase, ${\alpha}$-chymotrypsin, neutrase, papain, pepsin, and trypsin) to produce a collagenase-1 inhibitory peptide. The collagenase-1 inhibitory activity of the peptides obtained was measured by gelatin digestion assay. Among the six hydrolysates, pepsin hydrolysate exhibited the highest collagenase-1 inhibitory activity. The peptide showing strong collagenase-1 inhibitory activity was purified by Sephadex G-25 gel chromatography and HPLC using an octadecylsilyls (ODS) column. The amino acid sequence of purified collagenase-1 inhibitory peptide was identified to be Asn-Leu-Asp-Val -Leu-Glu-Val-Phe (961 Da) by quadrupole time of flight (Q-TOF) and electrospray ionization mass spectrometry (ESI-MS) mass spectroscopy. The $IC_{50}$ value of purified peptide was 87.0 ${\mu}M$. Moreover, the peptide did not exhibit cytotoxic effects on human dermal fibroblast cell lines.

• Fisheries and Aquatic Sciences
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• 제19권10호
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• pp.42.1-42.10
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• 2016

The objectives of this study were to identify the histamine-forming bacteria and bacteriocin- producing lactic acid bacteria (LAB) isolated from Myeolchi-jeot according to sequence analysis of the 16S rRNA gene, to evaluate the inhibitory effects of the bacteriocin on the growth and histamine accumulation of histamine-forming bacteria, and to assess the physico-chemical properties of the bacteriocin. Based on 16S rRNA gene sequences, histamine-forming bacteria were identified as Bacillus licheniformis MCH01, Serratia marcescens MCH02, Staphylococcus xylosus MCH03, Aeromonas hydrophila MCH04, and Morganella morganii MCH05. The five LAB strains identified as Pediococcus acidilactici MCL11, Leuconostoc mesenteroides MCL12, Enterococcus faecium MCL13, Lactobacillus sakei MCL14, and Lactobacillus acidophilus MCL15 were found to produce an antibacterial compound with inhibitory activity against the tested histamine-producing bacteria. The inhibitory activity of these bacteriocins obtained from the five LAB remained stable after incubation at pH 4.0-8.0 and heating for 10 min at $80^{\circ}C$; however, the bacteriocin activity was destroyed after treatment with papain, pepsin, proteinase K, ${\alpha}$-chymotrypsin, or trypsin. Meanwhile, these bacteriocins produced by the tested LAB strains also exhibited histamine-degradation ability. Therefore, these antimicrobial substances may play a role in inhibiting histamine formation in the fermented fish products and preventing seafood-related food-borne disease caused by bacterially generated histamine.

• Asian-Australasian Journal of Animal Sciences
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• 제24권4호
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• pp.500-508
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• 2011

Forty-four Gansu Alpine Fine-wool lambs were used to study changes in the activities of three gastric and five pancreatic enzymes under grazing conditions between 0 and 56 days of age. The lambs were slaughtered on days 0, 3, 7, 14, 21, 28, 42 and 56, the abomasal contents, mucosa and pancreas were immediately removed and placed into liquid nitrogen and enzyme activities were determined. Gastric enzyme (chymosin, pepsin and pregastrc esterase) activities were relatively high at birth, especially chymosin, but decreased quickly between day 0 and 21. The activity of pepsin changed insignificantly with increasing age. There was no significant change in the pancreatic enzyme activities (trypsin, chymotrypsin, ${\alpha}$-amylase, lipase and lactase). The activity of trypsin was relatively higher than that of the other pancreatic enzymes, and lactase activity was low. These ontogenic patterns might be under the control of many gut regulatory peptides, the plasma concentrations of which changed simultaneously. Some gastric and pancreatic enzymes were correlated with plasma concentrations of these gut regulatory peptides.

• Preventive Nutrition and Food Science
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• 제10권3호
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• pp.239-243
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• 2005

Angiotensin I-converting enzyme (ACE) inhibitory activities of elk antler hydrolysates prepared with three kinds of proteases, pepsin, trypsin and $\alpha-chymotrypsin$, were investigated. The ACE inhibitory activity of the pepsinolytic hydrolysate was the highest with an $IC_{50}$ value of $9.3\mu g/mL.$ In addition, three kinds of pepsinolytic hydrolysates with relatively high molecular weights (over 10,000 Da), medium molecular weights (5,000 to 10,000 Da), and low molecular weights (below 5,000 Da) were fractionated using an ultrafiltration membrane system. The below 5,000 Da hydrolysate exhibited the highest ACE inhibitory activity. These results indicate that the pepsinolytic hydrolysates of elk velvet antler could be a good source of peptides with ACE inhibitory activity.

• Food Science and Biotechnology
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• 제18권5호
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• pp.1173-1179
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• 2009

Trypsin inhibitors and lectins are defense proteins produced by many organisms. From Chinese 'Large Black Soybeans', a 60 kDa lectin and a 20 Da trypsin inhibitor (TI) were isolated using chromatography on Q-Sepharose, Mono Q, and Superdex 75. The TI inhibited trypsin and chymotrypsin with an $IC_{50}$ of 5.7 and $5{\mu}M$, respectively. Trypsin inhibitory activity of the TI was stable from pH 3 to 13 and from 0 to $65^{\circ}C$. Hemagglutinating activity of the lectin was stable from pH 2 to 13 and from 0 to $65^{\circ}C$. The TI was inhibited by dithiothreitol, signifying the importance of disulfide bond. The TI and the lectin inhibited HIV-1 reverse transcriptase ($IC_{50}$=44 and $26{\mu}M$), and proliferation of breast cancer cells ($IC_{50}$=42 and $13.5{\mu}M$) and hepatoma cells ($IC_{50}$=96 and $175{\mu}M$). The hemagglutinating activity of the lectin was inhibited most potently by L-arabinose. Neither the lectin nor the TI displayed antifungal activity.

• Food Science and Biotechnology
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• 제16권4호
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• pp.572-575
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• 2007

The angiontensin converting enzyme (ACE) inhibitory peptides were separated from beef sarcoplasmic protein extract and their amino acid sequences were identified as GFHI, DFHINQ, FHG, and GLSDGEWQ. The 4 peptides were synthesized in a laboratory and the ACE inhibitory activities of pep tides was measured after 2 months of storage at $4^{\circ}C$ under different pH conditions (6.0, 6.5, 7.0, 7.5, and 8.0) and the exposure of different temperatures (70, 80, 90, and $100^{\circ}C$) for 20 min to evaluate industrial use. No significant difference was detected by pH and temperature abuse for 20 min during storage. When the synthetic peptides were digested by pepsin, trypsin, and chymotrypsin, the ACE inhibitory activity was not changed. These results indicated that the 4 synthetic peptides with ACE inhibitory activity were pH-stable, heat-stable, and resistant to proteinases in gastro-intestinal tracts. Therefore, those 4 peptides can be used as a source for functional food product with various applications.