Evaluation of peptide adsorption-controlled liquid chromatography–tandem mass spectrometric (PAC-LC–MS/MS) method for simple and simultaneous quantitation of amyloid β 1–38, 1–40, 1–42 and 1–43 peptides in dog cerebrospinal fluid

The Pathogenic Aβ43 Is Enriched in Familial and Sporadic Alzheimer Disease

“…Concentrations in CSF of both Aβ42 and Aβ43 were significantly lower in the patients compared with control subjects indicating an accumulation of these peptides in the brain. Moreover, Aβ43 has been identified in dog CSF in a study using peptide adsorption – liquid chromatography – tandem mass spectrometry [38]. Although these recent publications have shed more light on Aβ43, more studies are warranted to learn more about the impact of Aβ43 on AD pathogenesis.…”

Simultaneous quantification of intracellular and secreted active and inactive glucagon-like peptide-1 from cultured cells

“…To overcome this adsorptive sample loss problem, we (i) used organic solvents to prevent adsorption, (ii) analyzed the peptides immediately after sample preparation (thereby avoiding any freeze-thaw steps), and (iii) prepared stable isotope-labeled internal standard peptides and added them directly into the collected samples. Goda and Kobayashi employed a method called peptide adsorption-controlled liquid chromatography-tandem mass spectrometry (PAC-LC-MS/MS) to analyze the hydrophilic amyloid-b peptides (Ab38, Ab40, Ab42, and Ab43) in dog cerebrospinal fluid samples [34]. In this technique, they used their original parameter of adsorption capacity of polypeptides to overcome the adsorption problem for Ab peptides.…”

Microbial degradation of linear peptides by strain B-9 of Sphingosinicella and its application in peptide quantification using liquid chromatography-mass spectrometry

“…Therefore, we set the incubation time to 15 h for the generation of surrogate peptide GLP-1 7-23 of GLP-1. GIP 1-8 was added as an internal standard after the incubation, because it has been used as the surrogate peptide in the quantification method of GIP , and the recovery rate after solid-phase extraction using OASIS MAX was sufficient (7 6 , and b 5 ions, respectively. Linearity was evaluated between 1, 2, 10, 50, 200 and 500 nM GLP-1.…”

“…However, larger intact peptides such as glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptides (GIP), as well as proteins, are more difficult to analyze by electrospray ionization mass spectrometry (ESI/MS) because of the occurrence of many multiple charge states (4) and occasional adsorption problems during sample preparation (3,5,6). To overcome undesirable properties, Siskos et al proposed the use of a surrogate peptide (4).…”

“…Then, samples were incubated at 27 C for 15 h. After incubation, 10 mL of GIP 1-8 solution was added as an internal standard to all samples, resulting in a final plasma concentration of 500 nM for GIP[1][2][3][4][5][6][7][8] .…”