{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T04:10:25Z","timestamp":1773288625254,"version":"3.50.1"},"reference-count":58,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2013,1,11]],"date-time":"2013-01-11T00:00:00Z","timestamp":1357862400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>In an effort to develop short antimicrobial peptides with simple amino acid compositions, we generated a series of undecapeptide isomers having the L5K5W formula. Amino acid sequences were designed to be perfectly amphipathic when folded into a helical conformation by converging leucines onto one side and lysines onto the other side of the helical axis. The single tryptophans, whose positions were varied in the primary structures, were located commonly at the critical amphipathic interface in the helical wheel projection. Helical conformations and the tryptophanyl environments of the 11 L5K5W peptides were confirmed and characterized by circular dichroism, fluorescence and nuclear magnetic resonance spectroscopy. All of the isomers exhibited a potent, broad-spectrum of antibacterial activity with just a slight variance in individual potency, whereas their hemolytic activities against human erythrocytes were significantly diversified. Interestingly, helical dispositions and fluorescence blue shifts of the peptides in aqueous trifluoroethanol solutions, rather than in detergent micelles, showed a marked linear correlation with their hemolytic potency. These results demonstrate that our de novo design strategy for amphipathic helical model peptides is effective for developing novel antimicrobial peptides and their hemolytic activities can be estimated in correlation with structural parameters.<\/jats:p>","DOI":"10.3390\/molecules18010859","type":"journal-article","created":{"date-parts":[[2013,1,11]],"date-time":"2013-01-11T11:16:17Z","timestamp":1357902977000},"page":"859-876","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Structural Characterization of de Novo Designed L5K5W Model Peptide Isomers with Potent Antimicrobial and Varied Hemolytic Activities"],"prefix":"10.3390","volume":"18","author":[{"given":"Seo-Jin","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Biotechnology, Research Institute for Biomedical and Health Science, College of Biomedical and Health Science, Konkuk University, Chungju, Chungbuk 380-701, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jae-Seok","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, Research Institute for Biomedical and Health Science, College of Biomedical and Health Science, Konkuk University, Chungju, Chungbuk 380-701, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yoo-Sup","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, Research Institute for Biomedical and Health Science, College of Biomedical and Health Science, Konkuk University, Chungju, Chungbuk 380-701, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dae-Won","family":"Sim","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, Research Institute for Biomedical and Health Science, College of Biomedical and Health Science, Konkuk University, Chungju, Chungbuk 380-701, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sung-Hee","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, Research Institute for Biomedical and Health Science, College of Biomedical and Health Science, Konkuk University, Chungju, Chungbuk 380-701, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Young-Yil","family":"Bahk","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, Research Institute for Biomedical and Health Science, College of Biomedical and Health Science, Konkuk University, Chungju, Chungbuk 380-701, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kwang-Ho","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, Research Institute for Biomedical and Health Science, College of Biomedical and Health Science, Konkuk University, Chungju, Chungbuk 380-701, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eun-Hee","family":"Kim","sequence":"additional","affiliation":[{"name":"Division of Magnetic Resonance, Korea Basic Science Institute, Ochang, Chungbuk 363-883, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sung-Jean","family":"Park","sequence":"additional","affiliation":[{"name":"College of Pharmacy, Gachon University, 534-2 Yeonsu 3-dong, Yeonsu-gu, Incheon 406-799, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bong-Jin","family":"Lee","sequence":"additional","affiliation":[{"name":"Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hyung-Sik","family":"Won","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, Research Institute for Biomedical and Health Science, College of Biomedical and Health Science, Konkuk University, Chungju, Chungbuk 380-701, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2013,1,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"887","DOI":"10.1038\/jid.2011.387","article-title":"Antimicrobial peptides: Old molecules with new ideas","volume":"132","author":"Nakatsuji","year":"2012","journal-title":"J. Invest. Dermatol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1038\/nrd3591","article-title":"Designing antimicrobial peptides: Form follows function","volume":"11","author":"Fjell","year":"2012","journal-title":"Nat. Rev. Drug Discov."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"464","DOI":"10.1016\/j.tibtech.2011.05.001","article-title":"The expanding scope of antimicrobial peptide structures and their modes of action","volume":"29","author":"Nguyen","year":"2011","journal-title":"Trends Biotechnol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"440","DOI":"10.4161\/viru.1.5.12983","article-title":"Antimicrobial peptides: The ancient arm of the human immune system","volume":"1","author":"Wiesner","year":"2010","journal-title":"Virulence"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1007\/s00109-006-0143-4","article-title":"Multifunctional antimicrobial peptides: Therapeutic targets in several human diseases","volume":"85","author":"Zaiou","year":"2007","journal-title":"J. Mol. Med."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"356","DOI":"10.1038\/nrmicro2546","article-title":"Paneth cells, antimicrobial peptides and maintenance of intestinal homeostasis","volume":"9","author":"Bevins","year":"2011","journal-title":"Nat. Rev. Microbial."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"725","DOI":"10.1530\/REP-10-0537","article-title":"Antimicrobial peptides and pregnancy","volume":"141","author":"Frew","year":"2011","journal-title":"Reproduction"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"17","DOI":"10.2332\/allergolint.10-RAI-0292","article-title":"Antimicrobial peptides in healthy skin and atopic dermatitis","volume":"60","year":"2011","journal-title":"Allergol. Int."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1159\/000329673","article-title":"Antimicrobial peptides in periodontal innate defense","volume":"15","author":"Gorr","year":"2012","journal-title":"Front Oral Biol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1007\/s00005-010-0089-7","article-title":"Antimicrobial peptides in the brain","volume":"58","author":"Su","year":"2010","journal-title":"Arch. Immunol. Ther. Exp."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1111\/j.1574-6968.2006.00156.x","article-title":"Anti-inflammatory activity of cationic peptide: Application to the treatment of acne vulgaris","volume":"257","author":"Coulson","year":"2006","journal-title":"FEMS Microbiol. Lett."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1615\/CritRevImmunol.v20.i5.40","article-title":"Cationic antimicrobial peptides and their multifunctional role in the immune system","volume":"20","author":"Scott","year":"2000","journal-title":"Crit. Rev. Immunol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"933","DOI":"10.1517\/13543784.15.8.933","article-title":"Cationic antimicrobial peptides as novel cytotoxic agents for cancer treatment","volume":"15","author":"Mader","year":"2006","journal-title":"Expert Opin. Investig. Drugs"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"784","DOI":"10.1007\/s00018-005-4560-2","article-title":"Host defense peptides as new weapons in cancer treatment","volume":"62","author":"Papo","year":"2005","journal-title":"Cell. Mol. Life Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"216","DOI":"10.2337\/diabetes.55.01.06.db05-1108","article-title":"Natural antibiotics and insulin sensitivity: The role of bactericidal\/permeability-increasing protein","volume":"55","author":"Gubern","year":"2006","journal-title":"Diabetes"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.regpep.2009.07.014","article-title":"Gaegurin-6 stimulates insulin secretion through calcium influx in pancreatic \u03b2 Rin5mf cells","volume":"159","author":"Kim","year":"2009","journal-title":"Regul. Pept."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1582","DOI":"10.1016\/j.bbamem.2008.10.020","article-title":"Antimicrobial peptide mimics for improved therapeutic properties","volume":"1788","author":"Rotem","year":"2009","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_18","first-page":"217","article-title":"Will new generations of modified antimicrobial peptides improve their potential as pharmaceuticals?","volume":"38","author":"Brogden","year":"2011","journal-title":"Int. J. Antimicrob. Agents"},{"key":"ref_19","first-page":"228","article-title":"Antimicrobial peptides\u2014Promising alternatives to conventional antibiotics","volume":"20","author":"Baltzer","year":"2011","journal-title":"J. Mol. Microbiol. Biotechnol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"977","DOI":"10.1099\/jmm.0.011122-0","article-title":"Novel peptides therapeutics for treatment of infections","volume":"58","author":"Oyston","year":"2009","journal-title":"J. Med. Microbiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.regpep.2010.08.010","article-title":"De novo generation of short antimicrobial peptides with simple amino acid composition","volume":"166","author":"Lee","year":"2011","journal-title":"Regul. Pept."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1002\/psc.1149","article-title":"De novo generation of antimicrobial LK peptides with a single tryptophan at the critical amphipathic interface","volume":"15","author":"Kang","year":"2009","journal-title":"J. Pept. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1007\/s13238-010-0004-3","article-title":"Alpha-helical cationic antimicrobial peptides: Relationships of structure and function","volume":"1","author":"Huang","year":"2010","journal-title":"Protein Cell"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1436","DOI":"10.1016\/j.bbamem.2006.03.021","article-title":"Alpha-helical antimicrobial peptides\u2014Using a sequence template to guide structure-activity relationships studies","volume":"1758","author":"Zelezetsky","year":"2006","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"5589","DOI":"10.1046\/j.1432-1033.2001.02494.x","article-title":"Amphipathic \u03b1 helical antimicrobial peptides: A systematic study of the effects of structural and physical properties on biological activity","volume":"268","author":"Giangaspero","year":"2001","journal-title":"Eur. J. Biochem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1002\/1097-0282(2000)55:1<4::AID-BIP30>3.0.CO;2-M","article-title":"Amphipathic, \u03b1-helical antimicrobial peptides","volume":"55","author":"Tossi","year":"2000","journal-title":"Biopolymers"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1620","DOI":"10.1016\/j.bbamem.2008.10.021","article-title":"Action mechanism and structural requirements of the antimicrobial peptides, gaegurins","volume":"1788","author":"Won","year":"2009","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"4367","DOI":"10.1046\/j.1432-1033.2002.03139.x","article-title":"Effects of a tryptophanyl substitution on the structure and antimicrobial activity of C-terminally truncated gaegurin 4","volume":"269","author":"Won","year":"2002","journal-title":"Eur. J. Biochem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"14784","DOI":"10.1074\/jbc.M309822200","article-title":"Systematic peptide engineering and structural characterization to search for the shortest antimicrobial peptide analogue of gaegurin 5","volume":"279","author":"Won","year":"2004","journal-title":"J. Biol. Chem."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"4886","DOI":"10.1021\/jm050996u","article-title":"Structural determinants for the membrane interaction of novel bioactive undecapeptides derived from gaegurin 5","volume":"49","author":"Won","year":"2006","journal-title":"J. Med. Chem."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1007\/s10059-011-0005-y","article-title":"Activity optimization of an undecapeptide analogue derived from a frog-skin antimicrobial peptide","volume":"31","author":"Won","year":"2011","journal-title":"Mol. Cells"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1021\/bi00699a001","article-title":"Conformational parameters for amino acids in helical, \u03b2-sheet, and random coil regions calculated from proteins","volume":"13","author":"Chou","year":"1974","journal-title":"Biochemistry"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"422","DOI":"10.1016\/S0006-3495(98)77529-0","article-title":"A helix propensity scale based on experimental studies of peptides and proteins","volume":"75","author":"Pace","year":"1998","journal-title":"Biophys. J."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1093\/protein\/5.3.213","article-title":"The functions of tryptophan residues in membrane proteins","volume":"5","author":"Schiffer","year":"1992","journal-title":"Protein Eng."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"6521","DOI":"10.1021\/bi000073v","article-title":"Analysis of the role of interfacial tryptophan residues in controlling the topology of membrane proteins","volume":"39","author":"Ridder","year":"2000","journal-title":"Biochemistry"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1380","DOI":"10.1021\/bi201880s","article-title":"Role of the helical structure of the N-terminal region of Plasmodium falciparummerozoite surface protein 2 in fibril formation and membrane interaction","volume":"51","author":"Zhang","year":"2012","journal-title":"Biochemistry"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"12096","DOI":"10.1021\/bi9013819","article-title":"SDS micelles as a membrane-mimetic environment for transmembrane segments","volume":"48","author":"Tulumello","year":"2009","journal-title":"Biochemistry"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1002\/mrc.1816","article-title":"Solution NMR of membrane proteins: Practice and challenges","volume":"44","author":"Sanders","year":"2006","journal-title":"Magn. Reson. Chem."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"9540","DOI":"10.1021\/bi961644f","article-title":"Self-assembly of designed antimicrobial peptides in solution and micelles","volume":"36","author":"Javadpour","year":"1997","journal-title":"Biochemistry"},{"key":"ref_40","first-page":"1090","article-title":"Cell selectivity of an antimicrobial peptide melittindiastereomer with D-amino acid in the leucine zipper sequence","volume":"40","author":"Zhu","year":"2007","journal-title":"J. Biochem. Mol. Biol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"12316","DOI":"10.1074\/jbc.M413406200","article-title":"Rational design of \u03b1-helical antimicrobial peptides with enhanced activities and specificity\/therapeutic index","volume":"280","author":"Chen","year":"2005","journal-title":"J. Biol. Chem."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"851","DOI":"10.1128\/AAC.27.5.851","article-title":"Occurrence of a \u03b2-lactam-inducible penicillin-binding protein in methicillin-resistant staphylococci","volume":"5","author":"Ubukata","year":"1985","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"2276","DOI":"10.1016\/j.peptides.2007.09.010","article-title":"A library of linear undecapeptides with bactericidal activity against phytopathogenic bacteria","volume":"28","author":"Badosa","year":"2007","journal-title":"Peptides"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"3302","DOI":"10.1128\/AEM.72.5.3302-3308.2006","article-title":"Inhibition of plant-pathogenic bacteria by short synthetic cecropin A-melittin hybrid peptides","volume":"72","author":"Ferre","year":"2006","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1675","DOI":"10.1002\/bip.360321209","article-title":"Alpha-helix to random coil transitions: Determination of peptide concentration from the CD at the isodichroic point","volume":"32","author":"Holtzer","year":"1992","journal-title":"Biopolymers"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1695","DOI":"10.1002\/bip.360321211","article-title":"Helix propagation in trifluoroethanol solutions","volume":"32","author":"Storrs","year":"1992","journal-title":"Biopolymers"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"468","DOI":"10.1046\/j.1432-1327.1999.00641.x","article-title":"CD and NMR investigations on trifluoroethanol-induced step-wise folding of helical segment from scorpion neurotoxin","volume":"264","author":"Khandelwal","year":"1999","journal-title":"Eur. J. Biochem."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1016\/S0005-2760(98)00028-9","article-title":"The use of sodium dodecyl sulfate to model the apolipoprotein environment. Evidence for peptide-SDS complexes using pulsed-field-gradient NMR spectroscopy","volume":"1392","author":"Buchko","year":"1998","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"7948","DOI":"10.1021\/bi00149a028","article-title":"Tryptophan contributions to the unusual circular dichroism of fdbacteriophage","volume":"31","author":"Arnold","year":"1992","journal-title":"Biochemistry"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1182\/blood-2004-06-2067","article-title":"Rod mutations associated with MYH9-related disorders disrupt nonmuscle myosin-IIA assembly","volume":"105","author":"Franke","year":"2005","journal-title":"Blood"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"5113","DOI":"10.1021\/bi00438a031","article-title":"Interfacial properties and critical micelle concentration of lysophospholipids","volume":"28","author":"Stafford","year":"1989","journal-title":"Biochemistry"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1647","DOI":"10.1021\/bi00121a010","article-title":"The chemical shift index: A fast and simple method for the assignment of protein secondary structure through NMR spectroscopy","volume":"31","author":"Wishart","year":"1992","journal-title":"Biochemistry"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1016\/S0005-2736(01)00429-1","article-title":"General aspects of peptide selectivity towards lipid bilayers and cell membranes studied by variation of the structural parameters of amphipathic helical model peptides","volume":"1558","author":"Dathe","year":"2002","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1124\/pr.55.1.2","article-title":"Mechanisms of antimicrobial peptide action and resistance","volume":"55","author":"Yeaman","year":"2003","journal-title":"Pharmacol. Rev."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"2050","DOI":"10.1016\/j.peptides.2005.04.007","article-title":"Correlation between the activities of alpha-helical antimicrobial peptides and hydrophobicities represented as RP HPLC retention times","volume":"26","author":"Kim","year":"2005","journal-title":"Peptides"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1146\/annurev.bi.53.070184.003115","article-title":"Three-dimensional structure of membrane and surface proteins","volume":"53","author":"Eisenberg","year":"1984","journal-title":"Annu. Rev. Biochem."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/S0165-9936(98)00112-5","article-title":"Applications of circular dichroism in protein and peptide analysis","volume":"18","author":"Greenfield","year":"1999","journal-title":"Trends Analyt. Chem."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1093\/protein\/5.3.191","article-title":"Quantitative analysis of protein far UV circular dichroism spectra by neural network","volume":"5","author":"Muhr","year":"1992","journal-title":"Protein Eng."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/18\/1\/859\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:44:12Z","timestamp":1760219052000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/18\/1\/859"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,1,11]]},"references-count":58,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2013,1]]}},"alternative-id":["molecules18010859"],"URL":"https:\/\/doi.org\/10.3390\/molecules18010859","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2013,1,11]]}}}