Specific binding of 125I-labelled GLP-1(7-36)amide to rat lung membranes was dependent upon time and temperature and was proportional to membrane protein concentration. Binding was inhibited in a concentration-dependent manner by unlabelled GLP-1(7-36)amide consistent with the presence of a single class of binding sites with a dissociation constant (Kd) of 1.67 +/- 0.29 nmol/l. GLP-1(1-36)amide...

The carbonyl oxygen atom of the amide functional group is universally believed to be the thermodynamically preferred site of protonation in amides;[1] however, N protonation has been proposed to play a key role in biologically important reactions of peptides and proteins such as acid-catalyzed peptide hydrolysis[2] and cis ± trans isomerization about the CÿN bond.[3] Extensive research into the...

To determine the influence of glucagon-like peptides on the secretion of human pulmonary surfactant, we used human type II pneumocytes. In these cells, GLP-1(7-36) amide and exendin-4 stimulated phosphatidylcholine secretion (PC) and cAMP formation in a concentration-dependent manner; these effects were reversed by exendin(9-39). No changes were observed with other related peptides. The mechani...

An anharmonic vibrational Hamiltonian for the amide I, II, III, and A modes of N-methyl acetamide (NMA), recast in terms of the 19 components of an external electric field and its first and second derivative tensors (electrostatic DFT map), is calculated at the DFT(BPW91/6-31G(d,p)) level. Strong correlations are found between NMA geometry and the amide frequency fluctuations calculated using t...

Bacteria were enriched from soil samples with succinate as a carbon source and racemic naproxen nitrile [2-(6-methoxy-2-naphthyl)propionitrile] as sole source of nitrogen. Since naproxen nitrile was only poorly soluble in water media amended with different water-immiscible organic phases were used for the enrichments. With pristane (2,6,10,14-tetramethylpentadecane) as the organic phase two bac...

The presence or absence of peptide hormones in tissue extracts may in certain cases be demonstrated by exposing the extracts to conditions under which characteristic fragments of the polypeptide molecule in question are formed and then analyzing for such fragments. An approximate quantitation of the hormones may also be achieved thereby. In the present work the COOH-terminal fragments of polype...

Stipa robusta (= Stipa vaseyi) is a perennial grass found in certain areas of the southwestern United States. It is commonly known as sleepygrass, as horses that ingest this grass may become profoundly somnolent or stuporous for periods of time lasting up to several days. In an attempt to determine the active principle(s), fractionation of a methanolic extract of sleepygrass infected with an Ac...

Three allatostatins have been isolated from the mosquito Aedes aegypti. These peptides have the following structures: Ser-Pro-Lys-Tyr-Asn-Phc-Gly-Leu-amide, Leu-Pro-His-Tyr-Asn-Phe-Gly-Leu-amide, and Arg-Val-Tyr-Asp-Phe-Gly-Leu-amide. A cDNA encoding these peptides was isolated from an abdominal ganglia cDNA library and sequenced. It was found to encode two additional allatostatins: Ala-Ser-Ala...

Two new samples of poly(amide-imide)/nanocomposites containing bicyclo segment and dibenzalaceton moiety in the main chain were synthesized by a solution intercalation technique. Poly(amide-imide) (PAI) 8 as a source of polymer matrix was synthesized by the direct polycondensation reaction of N,N´-bis(4-carboxyphenyl)bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic diimide 3 with 2,6-bis(4-amino...

Five new aromatic poly(amide-imide)s (5a-e) were synthesized by direct polycondensationreaction of N-(4-carboxy phenyl) trimellitimide (3) with five aromatic diamines (4a-e) by usingtriphenyl phosphite in N-methyl-2-pyrrolidone (NMP) and pyridine at solution containingdissolved CaCl2. All of the polymers were obtained in quantitative yields with inherentviscosities between 0.29-0.40 dL/g. The r...