title: Amine modification of digested peptide at C-terminal end during protein digestion by protease.
abstract: We recently reported that C-terminal polyamine modification occurs when proteins are digested with trypsin in the presence of polyamine [Biochem. Biophys. Res. Commun., 356, 159-162 (2007)]. In the present study, the characteristics of this C-terminal modification in the presence of protease and amine were investigated. When hemoglobin (HB) was digested with trypsin in the presence of N-(2-pyridyl)-1,4-diaminobutane (Py4), formation of the modified peptide was dependent on time and on HB or Py4 concentration. When synthetic peptide was treated with trypsin in the presence of Py4, ca. 0.1% of the peptide was modified with Py4. When HB or cytochrome C was treated with a range of serine proteases in the presence of various amines (Py4, N-(2-pyridyl)-1,3-diaminopropane, tranexamic acid, isonicotinic acid hydrazide and ampicillin), the modified peptide was detected in all cases tested, thus suggesting that amine modification widely accompanies digestion by proteases.
authors.affiliation: Department of Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Sakado, Saitama, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ito
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Sugita
authors.forename: Koichi
authors.initials: K
authors.lastname: Takao
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Ikeguchi
authors.forename: Akira
authors.initials: A
authors.lastname: Shirahata
mesh_terms: D000588:Amines / Q000737:chemistry*; D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D006454:Hemoglobins / Q000737:chemistry; D006868:Hydrolysis; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D014357:Trypsin / Q000737:chemistry
chemical_list: D000588:Amines; D006454:Hemoglobins; D007202:Indicators and Reagents; D010455:Peptides; D012997:Solvents; D010447:Peptide Hydrolases; D014357:Trypsin