Abstract
During the last three decades, a variety of different studies on bioactive peptides that are opioid receptor ligands, have been carried out, with regard to their isolation and identification, as well as their molecular functions in living organisms. Thus, in this review, we would like to summarize the present state-of-the art concerning hemorphins, methodological aspects of their identification, and their potential role as therapeutic agents. We have collected and discussed articles describing hemorphins, from their discovery up until now, thus presenting a very wide spectrum of their characteristic and applications. One of the major assets of the present paper is a combination of analytical and pharmacological aspects of peptides described by a team who participated in the initial research on hemorphins. This review is, in part, focused on the analysis of endogenous opioid peptides in biological samples using advanced techniques, description of the identification of synthetic/endogenous hemorphins, their involvement in pharmacology, learning, pain and other function. Finally, the part regarding hemorphin analogues and their synthesis, has been added.
Highlights
Hemorphins are endogenous peptides that are known as “non-classical” or “atypical” opioid peptides
ELISA kits that are more suitable for the fast determination of hundreds of samples can be purchased from various vendors and are used for quantitation of hemorphins [36], but it should always be kept in mind that these techniques will provide general information on the “immunoreactive-like material”, despite characteristics of the antibody specificity attached to the kit, and that coelution with synthetic standard does not always reflect the real content under chromatographic peak when dealing with complex, endogenous material
In this paper we have discussed different studies on hemorphins performed from the very beginning and over the last 30 years, with a focus on the recent findings in the field of opioid peptides
Summary
Hemorphins are endogenous peptides that are known as “non-classical” or “atypical” opioid peptides. Hemorphins can be produced in vitro by endogenous lysosomal proteases [10], pepsin [11], pancreatic elastase [12] or cathepsin D [13,14] It is still uncertain which enzymes are responsible for the generation of hemorphins from hemoglobin chains. Other roles of hemoglobin, discovered much later, are based on the release of opioid peptides—hemorphins and longer sequences—hemocidins, possessing antibacterial properties [17]. The latter, is out of the scope of this review. G protein-coupled receptors (GPCRs) by hemorphins and their implication in physiology and pathophysiology [22]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
