Keire David A, Whitelegge Julian P, Bassilian Sara, Faull Kym F, Wiggins Brian W, Mehdizadeh Omid B, Reidelberger Roger D, Haver Alvin C, Sayegh Ayman I, Reeve Joseph R
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.
Regul Pept. 2008 Nov 29;151(1-3):61-70. doi: 10.1016/j.regpep.2008.04.001. Epub 2008 Apr 8.
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.
我们通过一种旨在防止和评估内源性肽降解的新提取方法，从紧邻盲肠的一部分犬回肠中纯化并鉴定了存在的肽YY（PYY）形式，并测定了它们的水平。我们使用了三个反相色谱步骤，并对各馏分进行放射免疫测定以检测PYY样免疫反应性（PYY-LI）。纯化后的馏分进行了完整蛋白质/肽质谱鉴定和测序（即“自上而下”的质谱分析）。该分析证实了一种新的PYY形式，即PYY(1-36)-Gly的身份，它在所用的所有三个分离步骤中均与PYY(1-36)-NH(2)共洗脱。PYY(1-36)-Gly形式约占犬肠道该区域中总PYY的20%。此外，我们还发现PYY(3-36)-NH(2)形式占犬回盲交界处总PYY的6%。PYY(1-36)的甘氨酸延伸形式的生理意义值得进一步研究。
