Endorphines: structure, rôles et biogénèse

1981 ◽  
Vol 59 (5) ◽  
pp. 413-431
Author(s):  
M. Chrétien ◽  
N. G. Seidah ◽  
H. Scherrer
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Opiate Receptors ◽  
Endocrine Control ◽  
Pain Transmission ◽  
Starting Point ◽  
Polypeptide Hormones ◽  
Regulatory Functions ◽  
The Brain ◽  
Lipolytic Hormones

The knowledge of the amino acid sequence of both β-lipotropin (β-LPH) and γ-LPH was the starting point that led to the hypothesis, considered revolutionary in 1967, that hormonal precursors exist. This concept was simultaneously proposed for proinsulin and applied later to other polypeptide hormones. The discovery of endorphins brought together two fields of research that were not related: the opiates and the so-called pituitary lipotropic hormones. The demonstration of specific brain opiate receptors led to the hypothesis of the existence of endogenous opiate ligands which could act as neurotransmittors. The isolation of such substances in the brain, first named enkephalins, revealed through their amino acid sequence their structural homology with the pituitary lipolytic hormones. The finding of a more potent opioid substance in the pituitary (β-endorphin) that comprises the last 31 amino acids of β-LPH shed a new light on the hypothesis proposed earlier which gave to β-LPH a role as a precursor molecule. Finally, the addition of ACTH completed a putative multipotent precursor model that has been recently named pro-opiomelanocortin. Pulse–chase experiments have definitely proven that β-endorphin is a maturation product of a large precursor also containing ACTH and MSH. In other studies, many groups have suggested that endorphins play important roles as possible neuromodulators in pain transmission, in analgesia, in tolerance and dependance, as well as on behavior and endocrine regulations, mainly those related to the hypothalamo–pituitary axes. The elucidation of the biosynthetic process or processes of cerebral endorphins (either enkephalins or β-endorphin) is of primary importance in order to understand better their biological as well as regulatory functions. These studies should also be applicable to the biosynthesis of all the other neuronal peptide hormones. It is hoped that they will provide new tools for the study of some important central nervous system functions, such as pain and endocrine control and the physiopathology of behavioral diseases.

scholarly journals Opiate receptors and opioid peptides: "The poppies of the mind"

1982 ◽  
Vol 1 (4) ◽  
pp. 195-198
Author(s):  
B. J. Meyer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Opioid Peptides ◽  
Opiate Receptors ◽  
The Mind ◽  
The Brain ◽  
Intensive Search

In 1964 β-lipotropin, a compound consisting of 91 amino acids, was isolated from the adenohypophysis. In 1973, opiate receptors were found to be present in different areas of the brain and it was postulated that the brain probably produces opiate-like substances which react with these receptors. This finding was followed with an intensive search for opiate-like substances, resulting in the isolation of two groups of substances which react with the opiate receptors. These were named the encephalins and the endorphins. All members of these two groups were either peptides or polypeptides and the amino-acid sequence of each corresponded to the amino-acid sequence of specific segments of β-lipotropin.

Association of the brain anion exchanger, AE3, with the repeat domain of ankyrin

1993 ◽  
Vol 105 (4) ◽  
pp. 1137-1142 ◽  
Author(s):  
C.W. Morgans ◽  
R.R. Kopito
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Anion Exchanger ◽  
Deletion Mutant ◽  
Tandem Repeats ◽  
Structural Homology ◽  
Terminal Domain ◽  
Repeat Domain ◽  
The Brain

The 89 kDa NH2-terminal domain of erythrocyte ankyrin is composed almost entirely of 22 tandem repeats of a 33 amino acid sequence and constitutes the binding site for the cytoplasmic NH2-terminal domain of the erythrocyte anion exchanger, AE1. We have developed an assay to evaluate the in vivo interaction between a fragment of ankyrin corresponding to this domain (ANK90) and two non-erythroid anion exchangers, AE2 and AE3, that share considerable structural homology with AE1. Association was assessed by co-immunoprecipitation of ANK90-anion exchanger complexes from detergent extracts of cells cotransfected with plasmids encoding the ankyrin fragment and the anion exchanger or mutants thereof. ANK90 was co-immunoprecipitated with AE1 but not with an AE1 deletion mutant lacking the cytoplasmic NH2-terminal domain. Using this assay, we show that the brain anion exchanger AE3, but not the closely related homologue, AE2, is capable of binding to ankyrin.

Peptides with Morphine-like Action in the Brain

1977 ◽  
Vol 130 (3) ◽  
pp. 298-304 ◽  
Author(s):  
Hans W. Kosterlitz ◽  
John Hughes
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Opioid Peptides ◽  
Endogenous Opioid Peptides ◽  
Endogenous Opioid ◽  
Methionine Enkephalin ◽  
Therapeutic Implications ◽  
The Brain ◽  
Development Of Tolerance

SummaryThe reasons which led to the search in the brain for substances with morphine-like actions are discussed. Two pentapeptides, methionine-enkephalin and leucine-enkephalin, were isolated. The amino acid sequence of methionine-enkephalin occurs also in the pituitary prohormone β-lipotropin, of which longer fragments (endorphins) of up to 31 amino acids exhibit strong morphine-like action.The physiological significance of these short and long opioid peptides is discussed, particularly with regard to their possible roles as neurotransmitter or neuromodulator.With regard to the mechanisms involved in the development of tolerance to and dependence on opiates, the importance of interaction between the endogenous opioid peptides and the exogenous opiate alkaloids is stressed.The possible therapeutic implications are discussed briefly.

scholarly journals Mast cell–glia axis in neuroinflammation and therapeutic potential of the anandamide congener palmitoylethanolamide

2012 ◽  
Vol 367 (1607) ◽  
pp. 3312-3325 ◽  
Author(s):  
Stephen D. Skaper ◽  
Laura Facci
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Therapeutic Potential ◽  
Naturally Occurring ◽  
Pain Transmission ◽  
Starting Point ◽  
Transmission Pathways ◽  
The Brain ◽  
Pro Inflammatory Cytokines

Communication between the immune and nervous systems depends a great deal on pro-inflammatory cytokines. Both astroglia and microglia, in particular, constitute an important source of inflammatory mediators and may have fundamental roles in central nervous system (CNS) disorders from neuropathic pain and epilepsy to neurodegenerative diseases. Glial cells respond also to pro-inflammatory signals released from cells of immune origin. In this context, mast cells are of particular relevance. These immune-related cells, while resident in the CNS, are able to cross a compromised blood-spinal cord and blood-brain barrier in cases of CNS pathology. Emerging evidence suggests the possibility of mast cell–glia communication, and opens exciting new perspectives for designing therapies to target neuroinflammation by differentially modulating the activation of non-neuronal cells normally controlling neuronal sensitization—both peripherally and centrally. This review aims to provide an overview of recent progress relating to the pathobiology of neuroinflammation, the role of glia, neuro-immune interactions involving mast cells and the possibility that glia–mast cell interactions contribute to exacerbation of acute symptoms of chronic neurodegenerative disease and accelerated disease progression, as well as promotion of pain transmission pathways. Using this background as a starting point for discussion, we will consider the therapeutic potential of naturally occurring fatty acid ethanolamides, such as palmitoylethanolamide in treating systemic inflammation or blockade of signalling pathways from the periphery to the brain in such settings.

scholarly journals A common structural blueprint for plant UDP-sugar-producing pyrophosphorylases

2011 ◽  
Vol 439 (3) ◽  
pp. 375-381 ◽  
Author(s):  
Leszek A. Kleczkowski ◽  
Matt Geisler ◽  
Elisabeth Fitzek ◽  
Malgorzata Wilczynska
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Molecular Mobility ◽  
Regulatory Mechanism ◽  
Catalytic Domain ◽  
Evolutionary Relationships ◽  
Amino Acid Sequence Level ◽  
Significant Homology ◽  
Regulatory Functions

Plant pyrophosphorylases that are capable of producing UDP-sugars, key precursors for glycosylation reactions, include UDP-glucose pyrophosphorylases (A- and B-type), UDP-sugar pyrophosphorylase and UDP-N-acetylglucosamine pyrophosphorylase. Although not sharing significant homology at the amino acid sequence level, the proteins share a common structural blueprint. Their structures are characterized by the presence of the Rossmann fold in the central (catalytic) domain linked to enzyme-specific N-terminal and C-terminal domains, which may play regulatory functions. Molecular mobility between these domains plays an important role in substrate binding and catalysis. Evolutionary relationships and the role of (de)oligomerization as a regulatory mechanism are discussed.

The staining pattern of the tropomyosin sequence is displayed in a new paracrystal

1986 ◽  
Vol 44 ◽  
pp. 150-151
Author(s):  
M.K. Lamvik ◽  
L.L. Klatt
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Staining Pattern ◽  
Banding Patterns ◽  
Mass Thickness ◽  
New Form

Tropomyosin paracrystals have been used extensively as test specimens and magnification standards due to their clear periodic banding patterns. The paracrystal type discovered by Ohtsuki1 has been of particular interest as a test of unstained specimens because of alternating bands that differ by 50% in mass thickness. While producing specimens of this type, we came across a new paracrystal form. Since this new form displays aligned tropomyosin molecules without the overlaps that are characteristic of the Ohtsuki-type paracrystal, it presents a staining pattern that corresponds to the amino acid sequence of the molecule.

Immunoelectron microscope detection of C-type natriuretic peptide in normal human atrial tissue

1993 ◽  
Vol 51 ◽  
pp. 388-389
Author(s):  
Chi-Ming Wei ◽  
Margaret Hukee ◽  
Christopher G.A. McGregor ◽  
John C. Burnett
Keyword(s):  
Amino Acid ◽  
Natriuretic Peptide ◽  
Vascular Tone ◽  
Cardiac Tissue ◽  
Ring Structure ◽  
Terminal Amino Acid ◽  
Amino Acid Peptide ◽  
Normal Human ◽  
Terminal Amino ◽  
The Brain

C-type natriuretic peptide (CNP) is a newly identified peptide that is structurally related to atrial (ANP) and brain natriuretic peptide (BNP). CNP exists as a 22-amino acid peptide and like ANP and BNP has a 17-amino acid ring formed by a disulfide bond. Unlike these two previously identified cardiac peptides, CNP lacks the COOH-terminal amino acid extension from the ring structure. ANP, BNP and CNP decrease cardiac preload, but unlike ANP and BNP, CNP is not natriuretic. While ANP and BNP have been localized to the heart, recent investigations have failed to detect CNP mRNA in the myocardium although small concentrations of CNP are detectable in the porcine myocardium. While originally localized to the brain, recent investigations have localized CNP to endothelial cells consistent with a paracrine role for CNP in the control of vascular tone. While CNP has been detected in cardiac tissue by radioimmunoassay, no studies have demonstrated CNP localization in normal human heart by immunoelectron microscopy.

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