Peptides bioactive

Fig. 1. Locations of bioactive peptides within human pro-opiomelanocortin for sites 131—267.

Two different mixtures of peptides and alkaloids (qv) have been analy2ed by ce/uv/ms using sims to determine whether this technique can detect trace impurities in mixtures (85). The first mixture consisted of two bioactive peptide analogues, which included Lys-bradykinin (kahidin) and Met-Lys-bradykinin. The presence of 0.1% Lys-bradykinin was detected by sim ce/ms but not by ce/uv at 0.1% level as it migrated from the capillary column prior to the main component, Met-Lys-bradykinin. The second mixture consisted of two antibacterial alkaloids, berberine and palmitine. The presence of 0.15% palmitine was detected by ce/uv and sim ce/ms at 0.15% level as it migrated from the capillary column, following the main component berberine. This technique can provide a complementary technique for trace components in such sample mixtures. 

The well-defined helical structure associated with appropriately substituted peptoid oligomers (Section 1.6) can be employed to fashion compounds that closely mimic the stracture and function of certain bioactive peptides. There are many examples of small helical peptides (<100 residues) whose mimicry by non-natural ohgomers could potentially yield valuable therapeutic and bioactive compounds. This section describes peptoids that have been rationaUy designed as mimics of antibacterial peptides, lung surfactant proteins, and coUagen proteins. Mimics of HIV-Tat protein, although relevant to this discussion, were described previously in this chapter (Sections 1.3.2 and 1.4.1). 

Translate Bioactive Peptide Sequences into Bioactive Peptoid Sequences... 

There have been notable successes in the replacement of individual peptide residues by peptoid monomers with retention of in vitro activity and enhancement of specificity. Unfortunately, attempts to completely transform those bioactive peptides that function via specific peptide-protein binding events into entirely pep-toid-based ohgomers have so far proven successful only at short chain lengths (e.g. [23]). It remains to be seen whether any general strategy can be developed in... 

Patch, J.A. and Barron, A.E. Mimicry of bioactive peptides by non-natural, sequence-specific peptidomimetic oligomers. Curr. Opin. Chem. Biol. 2002, 6, 872-877. 

Bioactive Peptides Based on Open-Chain y -Turn Mimetics... 

Niece KL, Hartgerink JD, Donners J et al (2003) Self-assembly combining two bioactive peptide-amphiphile molecules into nanofibers by electrostatic attraction. J Am Chem Soc 125 7146-7147... 

Niece KL, Czeisler C, Sahni V et al (2008) Modification of gelation kinetics in bioactive peptide amphiphiles. Biomaterials 29 4501 509... 

TAKAHASHI M, MORIGUCHI S, IKENO M, KONO S, OHATA K., USUI H, KURAHASHI K, SASAKI R, YOSHIKAWA M (1996) Studies on the Ueum-contracting mechanisms and identification as a complement C3a receptor agonist of oryzatensin, a bioactive peptide derived from rice albumin. Peptides. 17 5-12. 

TAKAHASHI M, MORIGUCHI s, YOSHIKAWA M, SASAKI R (1994) Isolation and characterization of oryzatensin a novel bioactive peptide with ileum-contracting and immimomodulating activities derived from rice albumin. Biochem Mol Biol Int. 33 1151-8. 

Dairy proteins are rich in nutrients and occupy a unique place of importance in food and human nutrition because of their wide acceptance in the world. Milk proteins are important in the diet because of the many health benefits associated with their consumption. The proteins have long been recognized as natural sources of health enhancing bioactive peptides because of their stmctural and physicochemical components as recently reviewed by Livney (2010). 

Surfactants, Detergents, and Enzymes Bioactive peptides, lytic enzymes, anionic surfactants Biodispersants and Biodetergents... 

Bioactive peptides such as superoxide dismutase and interferon arc also hoped to be accumulated in the inflamed and vascular lesions. However, these active peptides cannot be incorporated in lipid microspheres. Instead of incorporating them into lipid microspheres, we devised a method to combine the bioactive peptides with a chemically modified lecithin. In this study, we also examined the tissue distribution of lecithinized IgG. 

Neuropeptide S (NPS) is a recently discovered bioactive peptide that has emerged as a new signaling molecule in the complex circuitry that modulates sleep-wakefulness and anxiety-like behavior. The peptide precursor is expressed most prominently in a novel nucleus located in the perilocus coeruleus, a brain structure with well-defined functions in arousal, stress, and anxiety. NPS was also found to induce anxiolytic-like behavior in a battery of four different tests of innate responses to stress. Infusion of NPS potently increases wakefulness and suppresses non-REM (NREM) and REM sleep (Xu et al, 2004). NPS binds to a G-protein-coupled receptor, the NPS receptor, with nanomolar affinity activation of the receptor mobilizes intracellular calcium. The NPS receptor is expressed throughout the brain, particularly in regions relevant to the modulation of sleep and waking, in the tuberomammillary region, lateral hypothalamus, and medial thalamic nuclei. 

Pantarotto, D. et al. (2004) Translocation of bioactive peptides across cell... 

Currently, LC-MS is widely used for the analysis of polar compounds, such as medicinal metabolites and bioactive peptides, since the interface has been improved and several new ionization methods have been developed. The sensitivity and reproducibility are sufficient for a daily quantitative analysis. The usefulness of the LC-MS has been demonstrated for studies on Type II pheromones using a time-of-flight MS with electrospray ionization (ESI) [180]. Each epoxydiene derived from the (Z3,Z6,Z9)-triene shows three ion series of [M+NHJ+, [M+H]+, and [M-OH]+ with high resolution and good sensitivity, indicating its molecular formula. In addition to these, characteristic fragment... 

FIGURE 18-1 Selected bioactive peptides are grouped by structural similarity or by tissue source. 

FIGURE 1 8-3 Intracellular pathway of bioactive peptide biosynthesis, processing and storage. Neuropeptide precursors are synthesized on ribosomes at the endoplasmic reticulum and processed through the Golgi. Axonal transport of the large dense-core vesicle to the synaptic site of release precedes the actual secretion. 

FIGURE 1 8-5 Tissue-specific processing of the pro-opiomelanocortin (POMC) precursor yields a wide array of bioactive peptide products. Processing of the POMC precursor varies in various tissues. In anterior pituitary, adrenocorticotropic hormone (ACTH (1-39)) and P-1 ipo tropin (P-LPH) are the primary products of post-translational processing. Arcuate neurons produce the potent opiate P-endorphin (P-endo (1-31)) as well as ACTIK1 -13) NIT,. Intermediate pituitary produces a-melanocyte-stimulating hormone (aMSH), acetylated P endof 1 31) and P-endo(l-27). NTS, nucleus tractus solitarius. 

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