Peptide releaser

Apelins and the Apelin Receptor. Figure 3 Scheme illustrating the hypothesised mechanisms of control of human (a) vasculartone and (b) cardiac contractility by apelin peptides ( ). In the vasculature, apelins (released via the small vesicles of the constitutive pathway) may act directly to activate apelin receptors on the underlying smooth muscle to produce vasoconstriction. This response may be modified by apelin peptides feeding back onto apelin receptors on endothelial cells to stimulate the release of dilators, such as nitric oxide. In heart, apelin peptides, released from endocardial endothelial cells, activate apelin receptors on cardiomyocytes to elicit positive inotropic actions. 

Endogenous opioid peptide released both in the central nervous system and in other apparatuses of the body that have many regulatory functions, including inhibition of pain transmission. 

Measurement of a peptide released by the action of plasmin on both cross-linked and non-cross-linked fibrin, which is called Bp 15-42, is useful for the assessment of fibrinolytic activity (94). 

The amount of released ET-1 peptide was different for the two cell types at basal conditions, and was not altered by the presence of pro-inflammatory cytokines. The presence of HU significantly decreased the ET-1 peptide release from these two cell types (52% and 64% reduction for TrHBMEC and EA-hy 926 cells, respectively) under basal culture conditions (Figure 11.2). The magnitude of reduction... 

Fig. 11.4 Dose-response effect of HU on ET-1 peptide release (a) from TrHBM EC cells incubated with various concentrations of HU during 48 h in the presence (A) and absence ( ) of cytokines (TNFaand IFNy at 100 U mL 1). Under the same conditions, quantitative mRNA analysis was also performed and the residual percentage of expression, in the presence (b) and absence (c) of pro-inflammatory cytokines is given.

Fig. 11.6 Restoration of ET-1 peptide release (pgmL-1) after the removal of HU in the presence (a) and in the absence of (b) cytokines. The other experimental conditions were identical to those described in the legend to Figure 11.5.

The effects of both oxytocin and vasopressin are particularly responsive to reproductive steroids (Tables 7 and 8). Oxytocin and vasopressin are best known as neurohypophyseal peptides, released by the posterior pituitary. However, both peptides also are released within the nervous system. Receptors for oxytocin and vasopressin are distributed in areas of the CNS that have been implicated in reproduction, emotion and autonomic functions. 

Upon encountering a stop codon on the mRNA, the ribosome will halt incorporation of further amino acids into the polypeptide as there is no tRNA complementary to a stop codon (UAG, UGA, UAA). In order to liberate the polypeptide, the ester bond between the peptide and the tRNA residing in the P site has to be hydrolyzed — a reaction that is also catalyzed in the peptidyltransferase center. It is critical for protein synthesis that peptide release is tightly coupled to the presence of a stop codon in the decoding center to avoid premature termination resulting in shortened, nonfunctional proteins. Both functions, recognizing the stop codon and triggering... 

The new crystal structure of the ribosome—RFl complex sheds more light into the interactions between the GGQ motif and the peptidyltransferase center. This complex represents the product state of peptide release since a deacylated tRNA is bound to the P site. Importantly, the main chain amide of the conserved glutamine hydrogen bonds to the 3 OH of A76 in the P site, which is the leaving group of the hydrolysis... 

The assay involves a chromogenic tag such as pNA linked to a specific peptide corresponding to the cleavage site of the respective caspase. Proteolysis of this peptide releases the chromogenic tag, thereby increasing the chromophore intensity. 

Endothelin 1 (ETl) is a 21-amino acid peptide released from bronchial cells. It has potent vasoconstrictive agonist properties mediated by two receptor types (A and B). The involvement of the endothelin 1 type A (EDNRA) gene (Afill SNP) in atopy, however, is marginal at best and as yet not widely replicated (181). For... 

The hypothalamus is part of the brain. It is an important regulatory centre and produces a range of peptide-releasing and release-inhibiting hormones, which control the secretory activity of the pituitary. 

Proteins are first denatured by the stomach s hydrochloric acid (see p. 270), making them more susceptible to attack by the endopeptidases (proteinases) present in gastric and pancreatic juice. The peptides released by endopeptidases are further degraded into amino acids by exopeptidases. Finally, the amino acids are resorbed by the intestinal mucosa in cotransport with Na"" ions (see p. 220). There are separate transport systems for each of the various groups of amino acids. 

Identification of small peptides released during milk sterilization... 

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