Amine -peptide

Hymenoptera venoms are composed of biogenic amines and other low molecular weight substances, of basic peptides and of proteins. Injection of venom by Hymenoptera stings has toxic effects, due to biogenic amines, peptides and proteins biogenic amines such as histamine cause pain, are vasodilatory and increase... 

These systems rely on various combinations of size-exclusion chromatography, reversed-phase chromatography, and zone electrophoresis to characterize amines, peptides, and proteins (Yamamoto etal., 1989 Bushey and Jorgenson 1990 Larmann et al., 1993, Moore and Jorgenson, 1995 Optick and Jorgenson, 1997). Haleem Issaq reviews these separations in Chapter 16 of this book. 

We have already discussed the co-occurrence of small amine and peptide neurotransmitters their release is normally Ca + dependent, and they operate through signal transmission. They are also capable of regulating each other s release and even the synthesis, clustering, and affinity of receptors. Neuroendocrine cells are capable of producing more than one peptide, and thus an amine-peptide as well as a peptide-peptide combination is possible. It is known, for instance, that the vagus nerve contains substance P, vasointestinal peptide, enkephalin, cholecystokinin, and somatostatin— peptides with a hybrid combination of neural and hormonal communication properties. 

Nitrophenyl carbamates (R R2NC02Np) and related aryl carbamates, e.g. phenyl-, di-nitrophenyl-, trichlorophenyl-, and pentafluorophenyl carbamates, provide an additional route by which an Na-free peptide can be condensed with another amine (peptidic or... 

Method B Peptide Bond Formation in Solution Peptide-peptoid chains containing Gly-Pro-(iBu)Gly repeats were assembled by solid-phase methods, cleaved from the resin as N-terminal free amine and C-terminal amidated forms, and purified by RP-HPLC. The template KTA-(Gly-OH)3 (32) and free-amine peptide-peptoid chains were then coupled in soln using EDC and HOBt as the coupling reagents. The final products were separated by RP-HPLC yields 6-80%. Structures containing 1, 6, or 9 Gly-Pro-(iBu)Gly repeats were synthesized using this approach. 

ACh Amines Peptides Eicosanoids Nucleotide or nucleoside Others ... 

Material secreted from cells varies in character to include cationic amines, peptides, enzymes of large molecular weight and... 

Neuroendocrine cells occur in many organs and tissues in the body and are part of the diffuse neuroendocrine system, as described by Pearse and the dispersed neuroendocrine system, described by Gould and DeLellis. Not surprisingly, neuroendocrine cells and neoplasms formed by cells exhibiting neuroendocrine differentiation show similar immunohistochemical features. They contain a variety of biogenic amines, peptide hormones, and neurotransmitters that can be identified biochemically or immunohistochemically. Immunohistochemical markers are useful in showing neuroendocrine differentiation by a neoplasm but are not usually specific. The antibodies commonly employed in demonstrating neuroendocrine differentiation are shown in Table 12.10. 

Primary amines (peptides, pituitary extract neurophysin)... 

Amides. Esters derived from the N-hydroxy compound are active esters that undergo aminolysis in the dark at room temperature. In sterically demanding cases, the benzenesulfenamides R NSPh are more reactive than the free amines. Peptide formation has been demonstrated. 

Dansyl chloride Amino acids, phenols amines, peptides Fluorimetry (ex,340 em,510)... 

Further details of tissue distribution are reviewed by Pickles [10], and Horton [13] has tabulated some other circumstances in which prostaglandins are released. More recently it has been shown that they are also released by the isolated dog spleen in response to the infusion of particles [49] and during carrageenin-induced inflammation in the rat [50-51]. PGs (F5, and E2) occur in a wide variety of amine-peptide secreting tumours [52, 53]. 

In contrast to the early recognition of the importance of proline and proline-based secondary amine peptide catalysts as enzyme mimics, the potential of primary amines in asymmetric catalysis was much underestimated at that time, probably because of their known lower basicity in comparison to secondary amines. This is particularly surprising taking into consideration the fact that primary amino acid catalysis is of enormous importance in enzyme catalysis. For example, primaiy amines occur in the catalytic sites of several enzymes, such as type I aldolases, dehydratases, and decarboxylases. Therefore, primary amines as organocatalysts possess particular appeal. 

Amide formation from amine peptide synthesis when R is an amino acid derivative... 

The estimation of amines, amino acids, peptides and proteins is carried out by essentially the same procedure 2S2, 233]. Three volumes of a solution of a primary amine, peptide or protein in 0.05 M phosphate buffer, pH ft-9.5 (or a 0.05 M sodium borate buffer, pH 8-9.5) are mixed under vigorous stirring with 1 volume of fluorescamine solution (0.28 mg ml in acetone or 0.56 mg mlin dioxane). Fluorescence measurement is carried out 5—30 min after mixing. Yields of the fluorophore are 80—90%. There is a linear relationship betv/een the concentration of the amine and the observed fluorescence up to 25—30 nmol ml... 

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