A new endogenous form of PYY isolated from canine ileum: Gly-extended PYY(1-36).
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.
Keire
David A
DA
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.
Whitelegge
Julian P
JP
Bassilian
Sara
S
Faull
Kym F
KF
Wiggins
Brian W
BW
Mehdizadeh
Omid B
OB
Reidelberger
Roger D
RD
Haver
Alvin C
AC
Sayegh
Ayman I
AI
Reeve
Joseph R
JR
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
D019894:Peptide YY