TY - JOUR
T1 - Peptidomics of Cpefat/fat mouse hypothalamus
T2 - Effect of food deprivation and exercise on peptide levels
AU - Che, Fa Yun
AU - Yuan, Quan
AU - Kalinina, Elena
AU - Fricker, Lloyd D.
PY - 2005/2/11
Y1 - 2005/2/11
N2 - Carboxypeptidase E is a major enzyme in the biosynthesis of numerous neuroendocrine peptides. Previously, we developed a technique for the isolation of neuropeptide-processing intermediates from mice that lack carboxypeptidase E activity (Cpefat/fat mice) due to a naturally occurring point mutation. In the present study, we used a differential labeling procedure with stable isotopic tags and mass spectrometry to quantitate the relative changes in a number of hypothalamic peptides in Cpefat/fat mice in two different paradigms that each cause an ∼10% decrease in body mass. One paradigm involved a 2-day fast under normal sedentary conditions (i.e. standard mouse cages); the other involved giving mice access to an exercise wheel for 4 weeks with free access to food. Approximately 50 peptides were detected in both studies, and over 80 peptides were detected in at least one of the two studies. Twenty-eight peptides were increased >50% by food deprivation, and some of these were increased by 2- to 3-fold. In contrast, only three peptides were increased >50% in the group with exercise wheels, and many peptides showed a slight 15-30% decrease upon exercise. Approximately one-half of the peptides detected in both studies were identified by tandem mass spectrometry. Peptides found to be elevated by food deprivation but not exercise included a number of fragments of proenkephalin, prothyrotropin-releasing hormone, secretogranin II, chromogranin B, and pro-SAAS. Taken together, the differential regulation of these peptides in the two paradigms suggests that the regulation is not due to the lower body weight but to the manner in which the paradigms achieved this lower body weight.
AB - Carboxypeptidase E is a major enzyme in the biosynthesis of numerous neuroendocrine peptides. Previously, we developed a technique for the isolation of neuropeptide-processing intermediates from mice that lack carboxypeptidase E activity (Cpefat/fat mice) due to a naturally occurring point mutation. In the present study, we used a differential labeling procedure with stable isotopic tags and mass spectrometry to quantitate the relative changes in a number of hypothalamic peptides in Cpefat/fat mice in two different paradigms that each cause an ∼10% decrease in body mass. One paradigm involved a 2-day fast under normal sedentary conditions (i.e. standard mouse cages); the other involved giving mice access to an exercise wheel for 4 weeks with free access to food. Approximately 50 peptides were detected in both studies, and over 80 peptides were detected in at least one of the two studies. Twenty-eight peptides were increased >50% by food deprivation, and some of these were increased by 2- to 3-fold. In contrast, only three peptides were increased >50% in the group with exercise wheels, and many peptides showed a slight 15-30% decrease upon exercise. Approximately one-half of the peptides detected in both studies were identified by tandem mass spectrometry. Peptides found to be elevated by food deprivation but not exercise included a number of fragments of proenkephalin, prothyrotropin-releasing hormone, secretogranin II, chromogranin B, and pro-SAAS. Taken together, the differential regulation of these peptides in the two paradigms suggests that the regulation is not due to the lower body weight but to the manner in which the paradigms achieved this lower body weight.
UR - http://www.scopus.com/inward/record.url?scp=14244256205&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=14244256205&partnerID=8YFLogxK
U2 - 10.1074/jbc.M411178200
DO - 10.1074/jbc.M411178200
M3 - Article
C2 - 15572367
AN - SCOPUS:14244256205
SN - 0021-9258
VL - 280
SP - 4451
EP - 4461
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 6
ER -