• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.7-12
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• 1994

One bacterial strain, that had made the largest inhibition zone at the antagonism assay and also that lost the inhibition activity by the protease treatment, was isolated from raw milk. That strain was identified as Streptococcus salivarius subsp. thermophilus. The specific growht rate of this strain was maximum at 45$\circ $C. However, at this temperature the strain produced no bacteriocin. The bacteriocin activity was quite stable even at high temperature. Moreover, the activity of the vacteriocin was sensitive to proteases. but not to $\alpha $-amylase, DNase I, or RNase.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.351-358
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• 2013

A protease inhibitor from fish eggs was fractionated using chromatographic methods. The fractionation efficiency was evaluated in terms of specific inhibitory activity (SIA, U/mg), purity (fold), total inhibitory activity (TIA, U), and recovery (%). The protease inhibitor (PI) from egg extracts of skipjack tuna (ST Katsuwonus pelamis), yellowfin tuna (YT Thunnus albacares) and Alaska pollock (AP Theragra chalcogramma) was fractionated using Sephadex G-50 gel filtration and DEAE-Sepharose CL-6B anion exchange chromatography based on protein size exclusion and net charge, respectively. Fractions exhibiting strong inhibitory activity were contained in the 30-50 kDa fraction on gel filtration and in the range of 0.4-0.7 M NaCl gradient fraction on anion exchange chromatography. The respective TIA and percent recovery of the fraction obtained with gel filtration toward trypsin and $N{\alpha}$-benzoyl-L-arginine-p-nitroanilide (BAPNA) were 2,758.7 U and 29.6% for ST, 1,005.5 U and 25.6% for YT, and 1,267.5 U and 26.0% for AP. Gel filtration chromatography was more effective at fractionating PI than using ion exchange chromatography. These results suggest that fish eggs act as serine protease inhibitors and might be useful for protease inhibition in foodstuffs.

• Animal Bioscience
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• v.36 no.7
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• pp.1034-1043
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• 2023

Objective: Two serine protease inhibitors, peptidase inhibitor 3 (PI3) and secretory leukocyte protease inhibitor (SLPI), play important roles in protease inhibition and antimicrobial activity, but their expression, regulation, and function at the maternal-fetal interface in pigs are not fully understood. Therefore, we determined the expression and regulation of PI3 and SLPI in the endometrium throughout the estrous cycle and at the maternal-fetal interface in pigs. Methods: Endometrial tissues during the estrous cycle and pregnancy, conceptus tissues during early pregnancy, and chorioallantoic tissues during mid to late pregnancy were obtained, and the expression of PI3 and SLPI was analyzed. The effects of the steroid hormones estradiol-17β (E2) and progesterone (P4) on the expression of PI3 and SLPI were determined in endometrial explant cultures. Results: PI3 and SLPI were expressed in the endometrium during the estrous cycle and pregnancy, with higher levels during mid to late pregnancy than during the estrous cycle and early pregnancy. Early-stage conceptuses and chorioallantoic tissues during mid to late pregnancy also expressed PI3 and SLPI. PI3 protein and SLPI mRNA were primarily localized to endometrial epithelia. In endometrial explant cultures, the expression of PI3 was induced by increasing doses of P4, and the expression of SLPI was induced by increasing doses of E2 and P4. Conclusion: These results suggest that the PI3 and SLPI expressed in the endometrium and conceptus tissues play an important role in antimicrobial activity for fetal protection against potential pathogens and in blocking protease actions to allow epitheliochorial placenta formation.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.594-599
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• 2007

It is well known that the Escherichia coli inner membrane-bound protease DegS is a periplasmic stress sensor for unfolded outer membrane proteins (OMPs). Previous studies have also shown that the outer membrane protease OmpT activates plasminogen in vitro and this may be exploited by bacteria in the course of pathogenesis. However, there has been no research on the plasminogen activation ability of the important periplasmic protein DegS. Accordingly, in this study, the whole-length and truncated degS genes were separately overexpressed in Escherichia coli, the recombinant proteins purified by affinity chromatography, and their plasminogen activator role tested in vitro. The results suggested that the whole-length DegS was able to activate plasminogen on a plasma plate. The truncated form of DegS (residues 80-345), designated ${\Delta}DegS$, also acted as a plasminogen activator, as confirmed by different assays. The serine protease property of ${\Delta}DegS$ was verified based on the complete inhibition of its enzyme activity by PMSF (phenylmethanesulfonyl fluoride). Therefore, the present results indicate that DegS is a plasminogen activator in vitro.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.22-28
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• 2014

In this study, we conducted the anti-HIV-1 enzymes assay in vitro and its active components were predicted by QSAR in silico for the elucidation of action mechanism on anti-HIV of natural resources. The extracts of Gardenia jasminoides var. radicans Makino were tested for their inhibitory effects on the reverse transcriptase (RT), protease and ${\alpha}$-glucosidase. In the enzyme inhibition assay, the methanol extracts of Gardenia jasminoides var. radicans Makino stem showed a strong activity of 32.5% on the enzyme activity to cleave an oligopeptide, resembling one of the cleavage sites in the viral polyprotein which can only be processed by HIV-1 protease. Moreover the methanol extracts of stem exhibited alpha-glucosidase inhibitory activities of 26.1%. The methanol extracts ($100{\mu}g/ml$) of stem showed a weak activity of 13.4% on anti-HIV-1 RT using Enzyme Linked Oligonucleotide Sorbent Assay (ELOSA) method. However, all extracts of leaf and stem didn't exhibit the HIV-1-induced cytopathic effects with IC (inhibitory concentration) of $100{\mu}g/ml$ in HIV-1-infected human T-cell line. From these results, it is suggested that Gardenia jasminoides var. radicans Makino extracts may possibly be involved in the inhibition of reverse transcriptase, protease and alpha-glucosidase but can't vitally concerned with the viral replication in vitro.

• BMB Reports
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• v.30 no.2
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• pp.157-161
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• 1997

The present paper reports characteristics and specificity of the inhibitory action of $N^{\alpha}-tosyl-L-lysine-chloromethyl\;ketone$ (TLCK) and $N^{\alpha}-tosyl-L-phenylalanine-chloromethyl\;ketone$ (TPCK) on the glucose6-phosphate transporter of rat liver microsomes. The TLCK-induced inhibition was pH dependent. The inhibition constants for TPCK were determined by following pseudo-Lst order reaction mechanism. The inhibition was protected by preincubation with excess amount of glucose-6-phosphate. The results proved that (a) TLCK inactivates the microsomal glucose-6-phosphate transporter, (b) the inhibition results from the modification of sulfhydryl groups of the transporter.

• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.188-190
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• 1998

Penicillide, having a 5H, 7H-dibenzo［b,g］［1,5］ dioxocin-5-one skeleton, was isolated from the culture broth of Penicillium sp. F60760 as a nonpeptide inhibitor of calpain, a calcium-activated papain-like protease. The $IC_50$ value for the effect of penicillide against m-calpaln was $7.1{\mu}M$. However, penicillide did not inhibit papain at a concentration of $200{\mu}M$. These results suggest that penicillide is a new class of nonpeptide calpain inhibitor having an eight membered lactone ring.

• The Korean Journal of Mycology
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• v.36 no.2
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• pp.183-188
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• 2008

A fibrinolytic serine protease was purified from the fruiting bodies of an edible mushroom, Albatrellus confluens. The enzyme had a molecular mass of 30086.41 Da, as measured by MALDI-TOF mass spectrometry. The N-terminal amino acid sequence of the enzyme was Glu-Thr-Val-Thr-Glu-Thr-Thr-Ala -Pro-Trp-Gly-Leu-Ser-Arg-Ile. It displayed optimal activity at $50^{\circ}C$ and within a pH range of $8.0{\sim}10.0$, suggesting that the enzyme is an alkaline protease. The enzyme was stable up to $30^{\circ}C$. The enzyme displayed a strong substrate specificity for the synthetic peptide, N-Suc-Ala-Ala-Pro-Phe pNA. The enzyme activity was completely inhibited by addition of PMSF, indicating that the enzyme is a serine protease. No inhibition was observed following addition of E-64, pepstatin, or EDTA. The activity of the purified enzyme was decreased in the presence $Fe^{2+}$ or $Co^{2+}$, and the enzyme was completely inhibited by addition of $Hg^{2+}$. From these results, we propose that Albatrellus confluens could be used for biofunctional foods development and has potential therapeutic value for the treatment of vascular diseases.

• Food Science and Preservation
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• v.22 no.5
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• pp.727-734
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• 2015

In this study, three GRAS (generally recognized as safety) strain was isolated from Doenjang and Cheonggukjang and identified as a protease-producing microorganism, following the appearance of a clear zone around its colony when cultured on a medium containing skim milk. Based on an analysis of the nucleotide sequence of 16S ribosomal RNA, the strains wereas identified as Bacillus amyloliquefaciens and wereas therefore named Bacillus amyloliquefaciens CDD5, Bacillus amyloliquefaciens CPD4, and Bacillus amyloliquefaciens CGD3. Here, we analyzed the protease and ${\alpha}$-glucosidase inhibitory activities of the three B. amyloliquefaciens strains. Among the isolated strains, B. amyloliquefaciens CGD3 exhibited the highest protease activity (9.21 U/mL, 24 hr). The protease activities of B. amyloliquefaciens CDD5 and B. amyloliquefaciens CPD4 reached 1.14 U/mL and 8.02 U/mL, respectively, at 48 hr. The proteases from the three B. amyloliquefaciens strains showed the highest activities within a pH range of 8.0-9.0 at $50^{\circ}C$, and casein was found to be the preferred substrate on evaluating enzyme activity in the substrate specificity assay. The B. amyloliquefaciens strains exhibited maximal growth when the nutrient broth medium had an initial pH within the range of 5.0-10.0, 6-9% sodium chloride (NaCl), and 5% glucose. B. amyloliquefaciens CDD5 exhibited a low ${\alpha}$-glucosidase inhibition rate (5.32%), whereas B. amyloliquefaciens CPD4 and B. amyloliquefaciens CGD3 exhibited relatively higher inhibition rates of 96.89% and 97.55%, respectively.

• Applied Biological Chemistry
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• v.35 no.3
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• pp.191-195
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• 1992

In order to elucidate the plant-microorganism relationship, we purified an ethylene-inducible, basic 30 KD endochitinase from bean leaves and studied its antifungal activity by a hyphal extension-inhibition assay. The purified chitinase was effective in the inhibition of hyphal growth of Aspergillus fumigatus, Botrytis cinerea, Fusarium oxysporum, Rhizoctonia solani, while microbial chitinases of Serratia marcescens and Streptomyces griceus, egg white lysozyme and papya protease didn't affect hyphal growth of the fungi. The chitinase degraded the cell walls of Micrococcus lysodeikticus, suggesting the lysozyme activity of the chitinase. We discussed the implication of the bifunctional chitinase/lysozyme activities of the protein with hydrolysis of chitin in the rapidly extending hyphae of the fungi.