title: Complete amino acid sequence of a new murine T-cell growth factor P40.
abstract: A new murine T-cell growth factor, designated P40, which supports growth of helper T-cells in the absence of interleukin-2, interleukin-4 and antigen has been isolated from helper T-cell lines in sufficient quantities (100 micrograms) to permit its complete amino acid sequence determination. This was achieved by a combination of sensitive peptide mapping using microbore reversed-phase high performance liquid chromatography and automated microsequence analysis. Attempts to obtain N-terminal sequence data on P40 were unsuccessful due to N-terminal blockage of the native molecule. The nature of this N-terminal blocking was established using a combination of amino acid analysis, fast-atom-bombardment mass spectrometry and peptide synthesis. The P40 molecule, a single polypeptide chain comprising 126 amino acid residues, is structurally distinct from other known T-cell growth factors. No similarity was revealed when the amino acid sequence of P40 was compared with other proteins whose biochemical structure is known. The protein sequence data reported here predict four N-linked glycosylation sites in the P40 molecule.
authors.affiliation: Joint Protein Structure Laboratory, Ludwig Institute for Cancer Research (Melbourne Branch), Royal Melbourne Hospital, Parkville, Victoria, Australia.
authors.forename: R J
authors.initials: RJ
authors.lastname: Simpson
authors.forename: R L
authors.initials: RL
authors.lastname: Moritz
authors.forename: M R
authors.initials: MR
authors.lastname: Rubira
authors.forename: J J
authors.initials: JJ
authors.lastname: Gorman
authors.forename: J
authors.initials: J
authors.lastname: Van Snick
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D002999:Clone Cells; D003488:Cyanogen Bromide; D006023:Glycoproteins / Q000302:isolation & purification; D006133:Growth Substances / Q000302:isolation & purification; D016906:Interleukin-9; D013058:Mass Spectrometry; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000302:isolation & purification; D010447:Peptide Hydrolases; D010455:Peptides / Q000138:chemical synthesis; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014357:Trypsin
chemical_list: D006023:Glycoproteins; D006133:Growth Substances; D016906:Interleukin-9; D010446:Peptide Fragments; D010455:Peptides; D010447:Peptide Hydrolases; D014357:Trypsin; D003488:Cyanogen Bromide