title: Novel proline-hydroxyproline glycopeptides from the dandelion (Taraxacum officinale Wigg.) flowers: de novo sequencing and biological activity.
abstract: Two novel homologous peptides named ToHyp1 and ToHyp2 that show no similarity to any known proteins were isolated from Taraxacum officinale Wigg. flowers by multidimensional liquid chromatography. Amino acid and mass spectrometry analyses demonstrated that the peptides have unusual structure: they are cysteine-free, proline-hydroxyproline-rich and post-translationally glycosylated by pentoses, with 5 carbohydrates in ToHyp2 and 10 in ToHyp1. The ToHyp2 peptide with a monoisotopic molecular mass of 4350.3Da was completely sequenced by a combination of Edman degradation and de novo sequencing via top down multistage collision induced dissociation (CID) and higher energy dissociation (HCD) tandem mass spectrometry (MS(n)). ToHyp2 consists of 35 amino acids, contains eighteen proline residues, of which 8 prolines are hydroxylated. The peptide displays antifungal activity and inhibits growth of Gram-positive and Gram-negative bacteria. We further showed that carbohydrate moieties have no significant impact on the peptide structure, but are important for antifungal activity although not absolutely necessary. The deglycosylated ToHyp2 peptide was less active against the susceptible fungus Bipolaris sorokiniana than the native peptide. Unique structural features of the ToHyp2 peptide place it into a new family of plant defense peptides. The discovery of ToHyp peptides in T. officinale flowers expands the repertoire of molecules of plant origin with practical applications.
authors.affiliation: Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation.
authors.forename: Alexandra A
authors.initials: AA
authors.lastname: Astafieva
authors.affiliation: Division of Physiological Chemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Atim A
authors.initials: AA
authors.lastname: Enyenihi
authors.affiliation: Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation.
authors.forename: Eugene A
authors.initials: EA
authors.lastname: Rogozhin
authors.affiliation: Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation.
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Kozlov
authors.affiliation: Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation.
authors.forename: Eugene V
authors.initials: EV
authors.lastname: Grishin
authors.affiliation: Vavilov Institute of General Genetics, Russian Academy of Sciences, ul. Gubkina 3, Moscow, 119991, Russian Federation.
authors.forename: Tatyana I
authors.initials: TI
authors.lastname: Odintsova
authors.affiliation: Division of Physiological Chemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Roman A
authors.initials: RA
authors.lastname: Zubarev
authors.affiliation: Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russian Federation.
authors.forename: Tsezi A
authors.initials: TA
authors.lastname: Egorov
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D002942:Circular Dichroism; D035264:Flowers / Q000378:metabolism*; D006020:Glycopeptides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D006909:Hydroxyproline / Q000737:chemistry / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011392:Proline / Q000737:chemistry / Q000378:metabolism*; D020539:Sequence Analysis, Protein; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D031205:Taraxacum / Q000378:metabolism*
chemical_list: D006020:Glycopeptides; D011392:Proline; D006909:Hydroxyproline
keywords: Antimicrobial activity; Plant antimicrobial peptides; Proline-hydroxyproline-rich glycosylated peptides; Taraxacum officinale flowers; de novo sequencing