title: Evaluation and improvement of the properties of the novel cystine-knot microprotein McoEeTI for oral administration.
abstract: Cystine-knot microproteins exhibit several properties that make them highly interesting as scaffolds for oral peptide drug delivery. It was therefore the aim of the study to evaluate the novel clinically relevant cystine-knot microprotein McoEeTI regarding its potential for oral delivery. Additionally, based on the gained results, important features of McoEeTI were improved. Enzymatic degradation was caused by chymotrypsin, trypsin and porcine small intestinal juice whereas McoEeTI was stable towards elastase, membrane bound proteases, pepsin and porcine gastric juice. Only minor McoEeTI degradation was observed during a 24h incubation period in rat plasma. In the presence of various physiological ions about 50% of McoEeTI formed di- and/or trimers. P(app) value of McoEeTI was determined to be (7.4+/-0.4)x10(-6)cm/s. Sodium caprate and polycarbophil-cysteine (PCP-Cys) had no beneficial effect on McoEeTI permeation, whereas the utilization of a chitosan-thiobutylamidine (Chito-TBA) system improved McoEeTI permeation 3-fold. Enzymatic stability could be strongly improved by the utilization of Bowman-Birk-Inhibitor (BBI) as well as PCP-Cys. In conclusion, this study indicates that McoEeTI represents a promising candidate as a novel scaffold for oral peptide drug delivery.
authors.affiliation: ThioMatrix GmbH, Research Center Innsbruck, Mitterweg 24, 6020 Innsbruck, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Werle
authors.forename: K
authors.initials: K
authors.lastname: Kafedjiiski
authors.forename: H
authors.initials: H
authors.lastname: Kolmar
authors.forename: A
authors.initials: A
authors.lastname: Bernkop-Schnürch
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000284:Administration, Oral; D000595:Amino Acid Sequence; D000818:Animals; D002463:Cell Membrane Permeability; D002686:Chitin / Q000031:analogs & derivatives / Q000737:chemistry; D002918:Chymotrypsin / Q000737:chemistry / Q000378:metabolism; D047169:Cyclotides / Q000737:chemistry* / Q000235:genetics; D003545:Cysteine / Q000737:chemistry; D003553:Cystine / Q000737:chemistry / Q000235:genetics; D047168:Cystine Knot Motifs; D015194:Diffusion Chambers, Culture; D004337:Drug Carriers; D004355:Drug Stability; D007408:Intestinal Absorption; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics; D011487:Protein Conformation; D015202:Protein Engineering; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000737:chemistry* / Q000378:metabolism; D012694:Serine / Q000737:chemistry / Q000235:genetics; D013552:Swine; D013997:Time Factors; D014357:Trypsin / Q000737:chemistry / Q000378:metabolism; D014358:Trypsin Inhibitor, Bowman-Birk Soybean / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D047169:Cyclotides; D004337:Drug Carriers; C519458:McoEeTI protein; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D014358:Trypsin Inhibitor, Bowman-Birk Soybean; C493042:chitosan-4-thiobutylamidine; C063950:trypsin inhibitor EETI II protein, plant; C409923:trypsin inhibitor MCoTI-II; D002686:Chitin; D012694:Serine; D003553:Cystine; C030312:calcium polycarbophil; D002918:Chymotrypsin; D014357:Trypsin; D003545:Cysteine