• Food Science of Animal Resources
• /
• v.42 no.1
• /
• pp.46-60
• /
• 2022

In this study, angiotensin-I-converting enzyme inhibitory (ACEI) activity was evaluated in fermented goat milk fermented by lactic acid bacteria (LAB) from fermented foods and breast milk. Furthermore, the potential for ACEI peptides was identified in fermented goat milk with the highest ACEI activity. The proteolytic specificity of LAB was also evaluated. The 2% isolate was inoculated into reconstituted goat milk (11%, w/v), then incubated at 37℃ until pH 4.6 was reached. The supernatant produced by centrifugation was analyzed for ACEI activity and total peptide. Viable cell counts of LAB and titratable acidity were also evaluated after fermentation. Peptide identification was carried out using nano liquid chromatography mass spectrometry (LC-MS/MS), and potential as an ACEI peptide was carried out based on a literature review. The result revealed that ACEI activity was produced in all samples (20.44%-60.33%). Fermented goat milk of Lc. lactis ssp. lactis BD17 produced the highest ACEI activity (60.33%; IC₅₀ 0.297±0.10 mg/mL) after 48 h incubation, viable cell counts >8 Log CFU/mL, and peptide content of 4.037±0.27/mL. A total of 261 peptides were released, predominantly derived from casein (93%). The proteolytic specificity of Lc. lactis ssp. lactis BD17 through cleavage on the amino acid tyrosine, leucine, glutamic acid, and proline. A total of 21 peptides were identified as ACEI peptides. This study showed that one of the isolates from fermented food, namely Lc. lactis ssp. lactis BD17, has the potential as a starter culture for the production of fermented goat milk which has functional properties as a source of antihypertensive peptides.

• Parasites, Hosts and Diseases
• /
• v.60 no.2
• /
• pp.143-147
• /
• 2022

Acanthamoeba keratitis (AK) is a rare ocular disease, but it is a painful and sight-threatening infectious disease. Early diagnosis and adequate treatment are necessary to prevent serious complications. While AK is frequently diagnosis via several PCR assays or Acanthamoeba-specific antibodies, a more specific and effective diagnostic method is required. This study described the production of a polyclonal peptide antibody against the periplasmic binding protein (PBP) of A. castellanii and investigated its diagnostic potential. Western blot analysis showed that the PBP antibody specifically reacted with the cell lysates of A. castellanii. However, the PBP antibody did not interact with human corneal epithelial (HCE) cells and the other 3 major causative agents of keratitis. Immunocytochemistry (ICC) results revealed the specific detection of A. castellanii trophozoites and cysts by PBP antibodies when A. castellanii were co-cultured with HCE cells. PBP antibody specificity was further confirmed by co-culture of A. castellanii trophozoites with F. solani, S. aureus, and P. aeruginosa via ICC. The PBP antibody specifically reacted with the trophozoites and cysts of A. polyphaga, A. hatchetti, A. culbertsoni, A. royreba, and A. healyi, thus demonstrated its genus-specific nature. These results showed that the PBP polyclonal peptide antibody of A. castellanii could specifically detect several species of Acanthamoeba, contributing to the development of an effective antibody-based AK diagnostics.

• Food Engineering Progress
• /
• v.21 no.4
• /
• pp.360-366
• /
• 2017

Fish skin peptide-loaded liposomes were prepared in 100 mL and 1 L solution as lab scales, and 10 L solution as a prototype scale. The particle size and zeta potential were measured to determine the optimal conditions for the production of fish skin peptide-loaded liposome. The liposome was manufactured by the following conditions: (1) primary homogenization at 4,000 rpm, 8,000 rpm, and 12,000 rpm for 3 minutes; (2) secondary homogenization at 40 watt (W), 60 W, and 80 W for 3 minutes. From this experimental design, the optimal conditions of homogenization were selected as 4,000 rpm and 60 W. For the next step, fish peptides were prepared as the concentrations of 3, 6, and 12% at the optimum manufacturing conditions of liposome and stored at $4^{\circ}C$. Particle size, polydispersion index (pdI), and zeta potential of peptide-loaded liposome were measured for its stability. Particle size increased significantly as manufacture scale and peptide concentration increased, and decreased over storage time. The zeta potential results increased as storage time increased at 10 L scale. In addition, 12% peptide showed the formation of a sediment layer after 3 weeks, and 6% peptide was considered to be the most suitable for industrial application.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.1
• /
• pp.132-137
• /
• 2010

The skc gene encoding streptokinase (SK) with a molecular mass of approximately 47.4 kDa was cloned from Streptococcus equisimilis ATCC 9542 and heterologously overexpressed in Streptomyces lividans TK24 and E. coli using various strong promoters. When the promoter for sprT [Streptomyces griseus trypsin (SGT)] was used in the host S. lividans TK24, a 47.4-kDa protein was detected along with a smaller hydrolyzed protein (44 kDa), suggesting that posttranslational hydrolysis had occurred as has been reported in other expression systems. The casein/plasminogen plate assay revealed that the plasmid construct containing the SGT signal peptide was superior to that containing the SK signal peptide in terms of SK production. Maximal production of SK was calculated to be about 0.25 unit/ml of culture broth, a value that was five times higher than that obtained with other expression systems using ermE and tipA promoters in the same host. When the skc gene was expressed in E. coli BL21(${\Delta}DE3$)pLys under the control of the T7 promoter, a relatively large amount of SK was expressed in soluble form without hydrolysis. SK activity in E. coli/pET28a-$T7_pSK_m$ was more than 2 units/ml of culture broth, even though about half of the expressed protein formed an inactive inclusion body.

• BMB Reports
• /
• v.53 no.10
• /
• pp.539-544
• /
• 2020

Skin aging appears to be the result of overlapping intrinsic (including genetic and hormonal factors) and extrinsic (external environment including chronic light exposure, chemicals, and toxins) processes. These factors cause decreases in the synthesis of collagen type I and elastin in fibroblasts and increases in the melanin in melanocytes. Collagen Type I is the most abundant type of collagen and is a major structural protein in human body tissues. In previous studies, many products containing collagen derived from land and marine animals as well as other sources have been used for a wide range of purposes in cosmetics and food. However, to our knowledge, the effects of human collagen-derived peptides on improvements in skin condition have not been investigated. Here we isolate and identify the domain of a human COL1A2-derived protein which promotes fibroblast cell proliferation and collagen type I synthesis. This human COL 1A2-derived peptide enhances wound healing and elastin production. Finally, the human collagen alpha-2 type I-derived peptide (SMM) ameliorates collagen type I synthesis, cell proliferation, cell migration, and elastin synthesis, supporting a significant anti-wrinkle effect. Collectively, these results demonstrate that human collagen alpha-2 type I-derived peptides is practically accessible in both cosmetics and food, with the goal of improving skin condition.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2002.10a
• /
• pp.121-124
• /
• 2002

This work was initiated to develope a recombinant oral poliovaccine (OPV), which is highly advanced in safety (minimizing VAPP) by introducing Type 2,3 poliovirus epitopes into our RPS-Vax system. We have introduced several potential vaccine epitopes of poliovirus Type 2, and 3 into RPS-Vax system, resulting in production of recombinant polioviruses. Any of these chimeric viruses, however, were not detected for their foreign gene expression by serotype-specific mouse antiserum. We have designed several folding units to stabilize the introduced vaccine protein and attached short epitope-concatamer or epitope-multimer to them, followed by production of chimeric viruses. Only those who have an HIV-1 Tat-mediated folding unit were nicely detected for the introduced foreign proteins by anti-Tat antiserum and type-specific peptide-induced antisera. Nevertheless, introduced epitopes were not detected in Western blot experiment with each serotype-specific antiserum. None of the mice inoculated with these chimeric viruses showed preventative immunity when challenged with Lansing and Leon wildtype 2 and 3 poliovirus, and the antiserum did not show neutralizing capacity in vitro. Conformational epitope covering B/C loop region of type 2 and 3 were newly designed by computer modeling, and introduced into the RPS-Vax vector system, followed by production of chimeric viruses. Introduced epitope regions were nicely detected by anti-Tag23 mAb or peptide antibody, but still not detected by poliovirus antiserum. Nevertheless, neutralizing antibody was detected in the Tg-PVR mice even when inoculated once with these chimeric viruses. Also, the immunized mice showed perfect preventative immunity against the wild Type poliovirus Lancing or Leon. When boosted appropriately, those chimeric virus-inoculated Tg-PVR mice produced equivalent amounts of neutralizing antibody to those in Sabin 2/3-immunized mice. These data strongly suggest that our recombinant poliovirus (RPS-PV2 and RPS-PV3) can be used as a safe and effective rec-OPV instead of any preexisting poliovaccine.

• Microbiology and Biotechnology Letters
• /
• v.34 no.3
• /
• pp.221-227
• /
• 2006

BSCX1 was an antimicrobial peptide produced by Bacillus subtilis cx1. Attempts were made to determine the location of inducing factor in the bacteriocin-sensitive cell affecting bacteriocin BSCX1 production. Mixed culture of the bacteriocin producer strain B. subtilis cx1 and its sensitive strain B. subtilis ATCC6633, increased production of bacteriocin BSCX1. The result suggested the presence of a bacteriocin inducing factor in the sensitive strain. The inducing factor was localized in the cell debris and intracellular fraction of B. subtilis ATCC6633. Bacteriocin BSCX1 inducing factor was found to be highly stable in the pH range 2.5-9.5, but inactivated within 3h over $50^{\circ}C$, and treatment with proteinase K destroyed its inducing activity, this result suggested that the inducing factor should be a proteinaceous nature.

• IMMUNE NETWORK
• /
• v.3 no.2
• /
• pp.126-135
• /
• 2003

Background: One of the important factors in the prognosis of chronic hepatitis B patient is the degree of replication of hepatitis B virus (HBV). It has been known that HBV DNA polymerase plays the essential role in the replication of HBV. HBV DNA polymerase is composed of four domains, TP (Terminal protein), spacer, RT (Reverse transcriptase) and RNaseH. Among these domains, tyrosine, the $65^{th}$ residue of TP is an important residue in protein-priming reaction that initiates reverse transcription. If monoclonal antibody that recognizes around tyrosine residue were selected, it could be applied to further study of HBV replication. Methods: To produce TP-specific scFv (single-chain Fv) by phage display, mice were immunized using synthetic TP-peptide contains $57{\sim}80^{th}$ amino acid residues of TP domain. After isolation of mRNA of heavy-variable region ($V_H$) and light-chain variable region ($V_L$) from the spleen of the immunized mouse, DNA of $V_H$ and $V_L$ were obtained by RT-PCR and joined by a DNA linker encoding peptide (Gly4Ser)3 as a scFv DNA fragments. ScFv DNA fragments were cloned into a phagemid vector. scFv was expressed in E.coli TG1 as a fusion protein with E tag and phage gIII. To select the scFv that has specific affinity to TP-peptide from the phage-antibody library, we used two cycles of panning and colony lift assay. Results: The TP-peptide-specific scFv was isolated by selection process using TP-peptide as an antigen. Selected scFv had 30 kDa of protein size and its nucleotide sequences were analyzed. Indirect- and competitive-ELISA revealed that the selected scFv specifically recognized both TP-peptide and the HBV DNA polymerase. Conclusion: The scFv that recognizes the TP domain of the HBV DNA polymerase was isolated by phage display.

• Animal Bioscience
• /
• v.37 no.6
• /
• pp.1096-1109
• /
• 2024

Objective: This research aims to explore the nutritional and bioactive peptide properties of goat meat taken from various primal cuts, including the breast, shoulder, rib, loin, and leg, to produce these bioactive peptides during in vitro gastrointestinal (GI) digestion and absorption. Methods: The goat meat from various primal cuts was obtained from Boer goats with an average carcass weight of 30±2 kg. The meat was collected within 3 h after slaughter and was stored at -80℃ until analysis. A comprehensive assessment encompassed various aspects, including the chemical composition, cooking properties, in vitro GI digestion, bioactive characteristics, and the bioavailability of the resulting peptides. Results: The findings indicate that the loin muscles contain the highest protein and essential amino acid composition. When the meats were cooked at 70℃ for 30 min, they exhibited distinct protein compositions and quantities in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis profile, suggesting they served as different protein substrates during GI digestion. Subsequent in vitro simulated GI digestion revealed that the cooked shoulder and loin underwent the most significant hydrolysis during the intestinal phase, resulting in the strongest angiotensin-converting enzyme (ACE) and dipeptidyl peptidase-IV (DPP-IV) inhibition. Following in vitro GI peptide absorption using a Caco-2 cell monolayer, the GI peptide derived from the cooked loin demonstrated greater bioavailability and a higher degree of ACE and DPP-IV inhibition than the shoulder peptide. Conclusion: This study highlights the potential of goat meat, particularly cooked loin, as a functional meat source for protein, essential amino acids, and bioactive peptides during GI digestion and absorption. These peptides promise to play a role in preventing and treating metabolic diseases due to their dual inhibitory effects on ACE and DPP-IV.

• Journal of the Korean Society of Industry Convergence
• /
• v.2 no.1
• /
• pp.77-83
• /
• 1999

Grown in the secondary broth of production media, the strain Streptomyces albulus has increased more the production of its metabolite ${\varepsilon}$-poly-L-lysine, one of poly(amino acid)s used as disinfecting food additives, than the strain in the primary culture of growth nutrients. Having the strain removed, the large concentrate obtained by ultrafiltrating the secondary culture broth. The concentrated production broth exchanged into followed by detecting in UV flowcell at 220nm the peptide bond of the components eluting the adsorbed proteins and polylysine with NaCl salt of gradient concentration, and has separated into five components. Among them the component in the fourth peak fraction has proved to be the pure ${\varepsilon}$-poly-L-lysine after the portion being hydrolyzed the fraction with HCl into amino acid followed by being the composing amino acid analysis.