Detect more, novel endogenous peptides

Post-sampling proteolytic activity begins immediately, producing protein fragments that can mask endogenous peptides present at low levels. Rapid heat stabilization stops enzymatic changes and protein degaradation immediately and permanently.

Heat stabilization enables detection of low abundant endogenous peptides

Comparison of heat stabilized and snap frozen bovine hypothalamus tissue revealed a greater number of neuropeptides in heat stabilized samples. Heat stabilization has prevented post-sampling proteolytic degradation from masking neuropeptides during analysis.

LC-MS profile of heat stabilized bovine hypothalamus. Peaks corrsponding to endogenous neurosecretory peptides; VGF[489–506], CCK[21–44], GnRH, AL11, CLIP, HCNP and BAM-1745. 

LC-MS profile of snap frozen bovine hypothalamus.The most prominent peaks are degradation fragments of the Stathmin protein; Stathmin [2–20] and stathmin [2–22]. Stathmin fragments are used as a marker of poor sample quality.
Results courtesy of Colgrave et al. Neuropeptide profiling of the bovine hypothalamus: Thermal stabilization is an effective tool in inhibiting post-mortem degradation, Proteomics 2011

The use of radioimmunoassay (RIA) to measure peptide levels in brain tissue

The levels of four peptides in the dynorphin system measured using radioimmunoassay. In heat stabilized samples, levels of intact dynorphin peptides, A and B, and MEAP are higher than the further processed Leu-Enkephalin-Arg peptide. In snap frozen samples, there are lower levels for the intact peptides and higher level of the Leu-Enkephalin-Arg metabolite, due to continued enzymatic conversion post sampling and during extraction.

Levels of dynorphin peptides in radioimmunoassay of mouse hypothalamus. Heat stabilized samples are compared to snap frozen.
Results courtesy of Jenny Gustavsson and Prof. Ingrid Nylander, Uppsala University, Sweden.

Visit our User support zone to learn more on how to work with heat stabilized samples and view guidelines for several downstream analytical methods and the key parameters important to think about for each workflow.

Product information, Stabilizor Peptide Extraction Kit

"We discovered several novel, potentially bioactive, brain neuropeptides."
Prof. Per Andrén, Uppsala University, Sweden