Mass Spectrometry Approaches Empowering Neuropeptide Discovery and Therapeutics

Abstract

The discovery of insulin in the early 1900s ushered in the era of research related to peptides acting as hormones and neuromodulators, among other regulatory roles. These essential gene products are found in all organisms, from the most primitive to the most evolved, and carry important biologic information that coordinates complex physiology and behavior; their misregulation has been implicated in a variety of diseases. The evolutionary origins of at least 30 neuropeptide signaling systems have been traced to the common ancestor of protostomes and deuterostomes. With the use of relevant animal models and modern technologies, we can gain mechanistic insight into orthologous and paralogous endogenous peptides and translate that knowledge into medically relevant insights and new treatments. Groundbreaking advances in medicine and basic science influence how signaling peptides are defined today.

Identifying and Measuring Endogenous Peptides through Peptidomics

“…Most peptidomics approaches utilize mass spectrometry to identify peptides present in a complex mixture (e.g., tissue extracts) in a nontargeted manner (Figure ). − Broadly, peptidomics methods measure the molecular masses of ionized molecules present in a mixture (these are called the “parent ions”, at the “MS1” level). Measured molecules are then subjected to fragmentation, often by collision with an inert gas, which fractures peptides by cleaving along the amide backbone.…”

Assessment and Comparison of Database Search Engines for Peptidomic Applications

“…Peptidomics is the study of characterizing the suite of endogenous peptides in a biological system, and these analyses are typically performed with the goal of understanding which peptides may be involved in a specific biological process or disease and also identifying novel peptides as potential biomarkers. 1 In peptidomics, peptide identifications is performed in an untargeted manner, allowing for the identification of potentially hundreds to thousands of peptides within a sample. Liquid chromatography coupled to mass spectrometry (LC-MS) is typically the method by which peptidomic experiments are conducted.…”

Global Neuropeptidome Profiling in Response to Predator Stress in Rat: Implications for Post-Traumatic Stress Disorder

“…9 One kind of neuromodulators, neuropeptides (NPs), are widely present in all animal species. 10 NPs are cleaved from prohormones by endogenous peptidases and act through both autocrine and paracrine signaling. 11 They are involved in diverse fundamental biological activities, including reproduction, 12 food intake, 13 and sleep/circadian rhythm.…”

“…One kind of neuromodulators, neuropeptides (NPs), are widely present in all animal species . NPs are cleaved from prohormones by endogenous peptidases and act through both autocrine and paracrine signaling .…”

“…The techniques are limited due to their low-throughput, cost inefficiency, and time consumption. The emergence of liquid chromatography coupled with electrospray ionization (LC-ESI) with tandem mass spectrometry (MS/MS) makes large-scale identification of endogenous peptides possible and cost-effective. , With LC-MS/MS, only a minimal sample (as low as picomolar or even femtomolar) is necessary for accurate profiling. Additionally, specific information about peptide sequences with various post-translational modifications can be obtained.…”