• 생명과학회지
• /
• 제28권3호
• /
• pp.300-306
• /
• 2018

라이소자임은 선천성 면역 물질로 개불을 포함하는 여러 무척추동물의 병원균에 대한 방어에 주요하게 작용한다. 본 논문은 개불(Urechis unicinctus)의 체벽 조직 추출물로부터 무척추형 라이소자임의 정제와 그 특성에 관한 분석을 기술하고 있다. 체벽 추출물은 우선적으로 Sep-Pak C18 cartridge를 사용하여 부분적으로 분리되었으며, 분리된 분획 중 60% 메탄올에 용출된 분획이 Bacillus subtilis KCTC 1021에서 강한 항균활성을 나타내었다. 그 후 여러 단계의 역상과 이온교환 고속액체크로마토그래피(High Performance Liquid Chromatography, HPLC)를 사용하여 항균성 물질이 정제되었으며, 분자량은 약 14 kDa이었다. 이 단백질의 일차서열은 LC-MS/MS를 통해 분석되었으며, 얻은 부분적 아미노산 서열을 NCBI BLAST를 통하여 분석해 본 결과, 이 항균성 물질은 다른 동물들로부터 동정된 무척추동물형 라이소자임(invertebrate-type lysozyme)의 서열과 유사도를 가지고 있어, 체벽으로부터 정제된 개불 라이소자임(Urechis unicinctus invertebrate-type lysozyme from body wall, Uu-iLysb)으로 명명하였다. 개불 라이소자임의 활성을 확인하기 위하여 항균활성 및 라이소자임 효소 활성실험을 진행한 결과, 개불 라이소자임이 항균활성과 라이소자임 효소활성 모두 강하게 가지고 있는 것을 확인하였다.

• Journal of Dairy Science and Biotechnology
• /
• 제27권1호
• /
• pp.19-28
• /
• 2009

Lactoferrin was first identified 60 years ago as a "red protein" in bovine milk. Lactoferrin, one of the transferrin family proteins, is an iron-binding glycoprotein found in milk and various mucosal secretions; it is also released from activated neutrophils. Human lactoferrin has a molecular weight of 82.4 kDa and is composed of 702 or 692 amino acid residues. Bovine lactoferrin has a molecular weight of 83.1 kDa and is composed of 689 amino acid residues. Both lactoferrin and transferrin have the ability to bind two $Fe^{3+}$ ions, together with two ${CO_3}^{2-}$ ions with extremely high affinity; these proteins also have the ability to release this iron at low pH levels. The polypeptide chain in lactoferrin is folded into two globular lobes, representing the N-terminal and C-terminal halves. Both lobes have similar folding and 40% sequence identity. This protein is capable of multiple functions as described in various review papers, including antimicrobial, antiviral, antiinflammatory, anticancer, antioxidant, and cell growth-promoting activities. Lactoferrin also exhibits immunomodulating effects and plays an active role in the regulation of myelopoiesis and the inhibition of bacterial translocation.

• BMB Reports
• /
• 제33권1호
• /
• pp.49-53
• /
• 2000

PMAP-23 is a 23-residue antimicrobial peptide derived from porcine myloid cells. In order to investigate the effects of two Pro residues at positions 12 and 15 of PMAP-23 on antibiotic activity, two analogues in which Ala was substituted for Pro residue at position 12 or 15 were synthesized. $Pro^{12}{\rightarrow}Ala$ (PMAPl) or $Pro^{15}{\rightarrow}Ala$(PMAP2) substitution in PMAP-23 caused a significant reduction on antitumor and phospholipid vesicle-disrupting activities, but did not cause a significant effect on antibacterial activity. PMAP-23 displayed the type I ${\beta}-turn$ structure with a negative ellipticity at near 205 om in SDS micelle, whereas PMAP1 and PMAP2 had a somewhat ${\alpha}-helical$ propensity in TFE solution, as compared to PMAP-23. These results suggest that two Pro residues of positions 12 and 15 in PMAP-23 play important roles in the formation of ${\beta}-turn$ structure on lipid membrane and its ${\beta}-turn$ structure may be essential for antibiotic activity including phospholipid vesicle-disrupting property.

• 한국자기공명학회논문지
• /
• 제22권4호
• /
• pp.139-143
• /
• 2018

Short antimicrobial peptide, A4W, have been studied by molecular dynamics (MD) simulation in an explicit dodecylphosphocholine (DPC) micelle. Peptide was aligned with DPC micelle and transferred new peptide-micelle coordinates within the same solvent box using specific micelle topology parameters. After initial energy minimization and equilibration, the conformation and orientation of the peptide were analyzed from trajectories obtained from the RMD (restrained molecular dynamics) or the subsequent free MD. Also, the information of solvation in the backbone and the side chain of the peptide, hydrogen bonding, and the properties of the dynamics were obtained. The results showed that the backbone residues of peptide are either solvated using water or in other case, they relate to hydrogen bonding. These properties could be a critical factor against the insertion mode of interaction. Most of the peptide-micelle interactions come from the hydrophobic interaction between the side chains of peptide and the structural interior of micelle system. The interaction of peptide-micelle, electrostatic potential and hydrogen bonding, between the terminal residues of peptide and the headgroups in micelle were observed. These interactions could be effect on the structure and flexibility of the peptide terminus.

• Journal of Microbiology and Biotechnology
• /
• 제30권3호
• /
• pp.382-390
• /
• 2020

Periplanetasin-4 is an antimicrobial peptide with 13 amino acids identified in cockroaches. It has been reported to induce fungal cell death by apoptosis and membrane-targeted action. Analogs were designed by substituting arginine residues to modify the electrostatic and hydrophobic interactions accordingly and explore the effect of periplanetasin-4 through the increase of net charge and the decrease of hydrophobicity. The analogs showed lower activity than periplanetasin-4 against gram-positive and gram-negative bacteria. Similar to periplanetasin-4, the analogs exhibited slight hemolytic activity against human erythrocytes. Membrane studies, including determination of changes in membrane potential and permeability, and fluidity assays, revealed that the analogs disrupt less membrane integrity compared to periplanetasin-4. Likewise, when the analogs were treated to the artificial membrane model, the passage of molecules bigger than FD4 was difficult. In conclusion, arginine substitution could not maintain the membrane disruption ability of periplanetasin-4. The results indicated that the attenuation of hydrophobic interactions with the plasma membrane caused a reduction in the accumulation of the analogs on the membrane before the formation of electrostatic interactions. Our findings will assist in the further development of antimicrobial peptides for clinical use.

• Fisheries and Aquatic Sciences
• /
• 제20권12호
• /
• pp.31.1-31.11
• /
• 2017

Background: Liver-expressed antimicrobial peptide-2 (LEAP-2) is an important component of innate immune system in teleosts. In order to understand isoform-specific involvement and regulation of LEAP-2 genes in mud loach (Misgurnus mizolepis, Cypriniformes), a commercially important food fish, this study was aimed to characterize gene structure and expression characteristics of two paralog LEAP-2 isoforms. Results: Mud loach LEAP-2 isoforms (LEAP-2A and LEAP-2B) showed conserved features in the core structure of mature peptides characterized by four Cys residues to form two disulfide bonds. The two paralog isoforms represented a tripartite genomic organization, known as a common structure of vertebrate LEAP-2 genes. Bioinformatic analysis predicted various transcription factor binding motifs in the 5'-flanking regions of mud loach LEAP-2 genes with regard to development and immune response. Mud loach LEAP-2A and LEAP-2B isoforms exhibited different tissue expression patterns and were developmentally regulated. Both isoforms are rapidly modulated toward upregulation during bacterial challenge in an isoform and/or tissue-dependent fashion. Conclusion: Both LEAP-2 isoforms play protective roles not only in embryonic and larval development but also in early immune response to bacterial invasion in mud loach. The regulation pattern of the two isoform genes under basal and stimulated conditions would be isoform-specific, suggestive of a certain degree of functional divergence between isoforms in innate immune system in this species.

• Preventive Nutrition and Food Science
• /
• 제15권4호
• /
• pp.360-363
• /
• 2010

To enhance the expression and secretion of pediocin PA-1 from heterologous bacterial hosts, the promoter and deduced signal sequence (PS) of an $\alpha$-amylase gene from a Bifidobacterium adolescentis strain was fused with pediocin PA-1 structural and immunity genes (AB) and the resulting functions were evaluated in Escherichia coli. Two recombinant PCR products were created-one with just the deduced signal sequence and one with the sequence plus the Ser and Thr sequences that are the next two amino acids of the signal sequence. These two products, the PSAB (---AQA::KYY---) and PSABST (---AQA$\underline{ST}$::KYY---), respectively, were inserted into a TA cloning vector (yT&A) and named pPSAB, which was previously reported, and pPSABST. The two recombinant plasmid DNAs were transferred into E. coli JM109 and the transformants displayed antimicrobial activity, where the activity of E. coli JM109 (pPSAB) was stronger than that of E. coli JM109 (pPSABST), indicating that the ST amino acid residues were not necessary for secretion and might have even decreased the antimicrobial activity of recombinant pediocin PA-1.

• 한국동물위생학회지
• /
• 제38권1호
• /
• pp.25-30
• /
• 2015

Bee venom has been used as to prevent and treat bovine mastitis as natural antimicrobial compounds in some dairy cattle farms in Korea. It is needed to determine the residual of bee venom in milks of dairy cattle treated with bee venom. Since bee venom is not approved as a raw material for animal drugs, the preprocessing method to detect bee venom residual in milk and the tolerance limit for its residue has not been established yet in Korea. Therefore, the purpose of this study was to develop pre-processing method not affecting major component of bee venom for detection of its residue in milks using ultra-high performance liauid chromatography (UHPLC). In addition, bee venom residue was also analyzed in milk samples of dairy cattle treated for mastitis with bee venom using UHPLC with the developed pre-processing method in this study. As a result, melittin, histamin and phospolipase A2, the major components of bee venom, were all detected by UHPLC with the pre-processing method developed in this study. The results of this study suggest that the pre-processing method developed in this study can be useful to detect bee venom residue in dairy cattle milk. We also found that no bee venom residues were detected in milk samples collected from dairy cattle treated with bee venom after 1 and 3 days, respectively.

• 한국어병학회지
• /
• 제16권3호
• /
• pp.193-201
• /
• 2003

Mastoparan B (MPB)는 벌독으로부터 정제된 양친매성 $\alpha$-helical 구조를 취하면서 14개의 아미노산 잔기로 구성된 염기성 항균성 펩타이드로서 여러가지 생물막과 작용한다. 본 연구에서는 우리 나라 연안의 적조 (HABs, harmful algal blooms)를 일으키는 4종의 적조생물 (Alexandrium tamarense, Chattonella marina, Cochlodinium polykrikoides 및 Gymnodinium catenatum)에 대한 MPB의 살조효과를 조사하였다. MPB의 4종의 적조생물에 대한 살조효과는 31.3 $\mu{g}$/mL부터 500 $\mu{g}$/mL에서 세포의 lysis 또는 ecdysis와 같은 형태로 현미경으로 관찰할 수 있었다. 또한 MPB는 C. marina 및 C. polykrikorides에 대해서 A. tamarense와 G. catenatum보다 더욱 강한 살조효과를 나타내었다. 이러한 MPB의 HABs에 대한 살조효과연구는 새로운 살조물질을 개발하기 위한 자료가 될 것으로 생각된다.

• 한국어병학회지
• /
• 제17권2호
• /
• pp.123-130
• /
• 2004

꿀벌 (Apis mellifera)의 lymph 액으로부터 정제된 항균성 펩타이드인, Apidaecin Ⅰb는 18개의 아미노산 잔기로 구성된 염기성 non-helical 펩타이드이다. 본 연구에서는 우리나라 연안의 적조 (HABs, harmful algal blooms)를 일으키는 4종의 적조생물 (Alexandrium tamarense, Chattonella marina, Cochlodinium polykrikoides 및 Gymnodinium catenatum)에 대한 Apidaecin Ⅰb의 살조효과를 조사하였다. Apidaecin Ⅰb의 4종의 적조생물에 대한 살조효과는 12.5$\mu{g}/mL$부터 50$\mu{g}/mL$에서 세포의 lysis 또는 ecdysis와 같은 형태로 현미경으로 관찰할 수 있었다. 또한 Apidaecin Ⅰb는 C. marina에 대해서 A. tamarense, C. polykrikorides 및 G. catenatum보다 더욱 강한 살조효과를 나타내었다. 이러한 HABs에 대한 Apidaecin Ⅰb의 살조효과 연구는 새로운 살조물질을 개발하기 위한 자료가 될 것으로 생각된다.