title: A new endogenous form of PYY isolated from canine ileum: Gly-extended PYY(1-36).
abstract: We purified and identified the peptide YY (PYY) forms present and determined their levels from a portion of the canine ileum directly adjacent to the cecum by a new extraction method designed to prevent and evaluate degradation of endogenous peptides. We used three reverse phase chromatography steps with radioimmunoassay of fractions for PYY-like-immunoreactivity (PYY-LI). The purified fractions underwent intact protein/peptide mass spectrometry identification and sequencing (i.e. "top-down" MS analysis). This analysis confirmed the identity of a new form of PYY, PYY(1-36)-Gly, which co-elutes with PYY(1-36)-NH(2) through all three of separation steps used. The PYY(1-36)-Gly form represents approximately 20% of the total PYY found in this region of the canine intestine. In addition, we also found that the PYY(3-36)-NH(2) form represents 6% of the total PYY in the canine ileo-cecal junction. The physiological implication of the Gly-extended form of PYY(1-36) warrants further investigation.
authors.affiliation: CURE: Digestive Diseases Research Center, VA GLAHS, Los Angeles, CA 90073 and Digestive Diseases Division, David Geffen School of Medicine at UCLA, Los Angeles, CA 90024, United States.
authors.forename: David A
authors.initials: DA
authors.lastname: Keire
authors.forename: Julian P
authors.initials: JP
authors.lastname: Whitelegge
authors.forename: Sara
authors.initials: S
authors.lastname: Bassilian
authors.forename: Kym F
authors.initials: KF
authors.lastname: Faull
authors.forename: Brian W
authors.initials: BW
authors.lastname: Wiggins
authors.forename: Omid B
authors.initials: OB
authors.lastname: Mehdizadeh
authors.forename: Roger D
authors.initials: RD
authors.lastname: Reidelberger
authors.forename: Alvin C
authors.initials: AC
authors.lastname: Haver
authors.forename: Ayman I
authors.initials: AI
authors.lastname: Sayegh
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Reeve
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004285:Dogs; D007082:Ileum / Q000033:anatomy & histology / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D019894:Peptide YY / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification*; D011863:Radioimmunoassay; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
chemical_list: D019894:Peptide YY