Lipid mobilizing peptide

LIPID MOBILIZING PEPTIDE IN HOG PITUITARY AND HUAAAN URINE... 

The existence of adipokinetic neuropeptides was identified in locusts based upon the elevation of hemolymph lipids by CC extracts (4,5). Subsequent isolation and structural definition of Lom-AKH-I ( provided the basis for defined studies on fat body lipid mobilization using synthetic peptide. 

Structure-activity studies are an indirect method to investigate a possible interaction of AKH peptides with their receptor proteins. For various members of the AKH family a vast body of literature has accumulated, employing bioassays such as lipid mobilization in locusts and the tobacco hommoth Manduca sexta, carbohydrate mobilization in various cockroach species, the activation of phosphorylase in the larvae of M. sexta, or the inhibition of fatty acid synthesis in the fat body of locusts [10, 33, 37, 53]. Contrary to most other invertebrate neuropeptides, the insect members of the AKH family do not have a core sequence which is essential for potency, however, the N-terminal pGlu residue and the C-terminal amide are important, as well as the aromatics at position 4 and 8. To achieve full efficacy, all amino acids are apparently important. There is also no superagonist found and also no inhibitor. 

Key words MALDI, ion mobility, lipids, imaging, peptides, drugs, profiling. 

Figure 4.13. Model of peptide initiation of mast secretion. Insertion of the hydrophobic region of the peptide into the lipid bilayer properly orients the basic (+) groups at the N-terminus for binding to negatively charged membrane components. As a result, there is activation of the G protein complex with the subsequent generation of inositol triphosphate (IP ) and diacylglycerol (DAG). These intermediates then stimulate the mobilization of cellular Ca and possibly the transient influx of extracellular Ca as well as the activation ofprotein kinase C. As a consequence, the level of intracellular free ionized Ca is maintained at an elevated state. The end result is the exocytotic extrusion of secretory granules.

AAT is the major constituent of the tti-glohulin band on routine clinical serum electrophoresis. The two other relatively high concentration tt]-globulins, AAG and a-lipoprotein, do not stain well with peptide stains because of their high contents of CHO and lipid, respectively. Some genetic variants of AAT may be detectable by visual examination of the electrophoresis pattern because of altered mobility or decreased concentration. 

Q-ToF Metabolites, lipids, peptides Accurate mass MS/MS combination with ion mobility Limited availability and support... 

Nanosyn, Caliper Life Sciences, and most Carna catalytic assays rely on a microfluidics capillary electrophoresis (CE) technology commercialized by Caliper Life Sciences. These are non-radioactive assays that measure the change in electrophoretic mobility of the substrate (usually a fluorescent-labelled peptide or lipid) upon phosphorylation. Both substrate and product are measured in these assays enabling increased assay precision. Since... 

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