Detection of interactions of the beta-amyloid peptide with small molecules employing transferred NOEs.

The interaction of pineal hormone melatonin, the histological dye thioflavin T, and the olive tree polyphenol oleuropein, with the 28 amino acid residue N-terminal fragment of the beta-amyloid peptide (beta-AP) of Alzheimer's disease, [beta-AP(1-28)], was detected in solution through the observation of transferred NOEs (trNOEs) in 1D and 2D NOE spectroscopy (NOESY) experiments. The trNOE method is applied for the first time in the detection of interactions of soluble beta-AP(1-28) with small molecules and may provide a means of screening for the identification of possible inhibitors of the formation of neurotoxic beta-AP assemblies.

Architecturally induced multiresponsive vesicles from well-defined polypeptides: formation of gene vehicles.

A series of novel, partially labeled amphiphilic triblock copolypeptides, PLL-b-PBLG-d7-b-PLL, has been synthesized, where PLL and PBLG-d7 are poly(L-lysine hydrochloride) and poly(gamma-benzyl-d7-L-glutamate), respectively. The synthetic approach involved the sequential ring-opening polymerization (ROP) of gamma-benzyl-L-glutamate and epsilon-Boc-L-lysine N-carboxy anhydrides by a diamino initiator using high-vacuum techniques, followed by the selective deprotection of the Boc groups. Combined characterization results showed that the copolypeptides exhibit high degrees of molecular and compositional homogeneity.

Preparation of a selective receptor for ephedrine for the development of an optical spot test for the detection of ephedrine in human urine using stabilized in air lipid films with incorporated receptor.

The present technique describes the preparation of a selective receptor for ephedrine and a simple sensitive spot optical test for the rapid one-shot detection of ephedrine in human urine using lipid films with an incorporated receptor that are synthesized by a chemical reaction with a methacrylate polymer on a glass fiber filter. The selective receptor was synthesized using a resorcin[4]arene receptor and by transforming all the -OH groups into methoxy groups. The lipid films without this receptor provided fluorescence under a UV lamp.

A novel and efficient method for cleavage of phenacylesters by magnesium reduction with acetic acid.

[reaction: see text] In the present study, we use magnesium turnings as a new deprotection reagent for the phenacyl group during orthogonal organic synthesis in the presence of other esters and sensitive protecting groups. By applying the new magnesium turnings/acetic acid deprotection method, phenacyl group can be more easily combined with other protecting groups that are not compatible with the zinc/acetic acid method.

Comparative evaluation of four trityl-type amidomethyl polystyrene resins in Fmoc solid phase peptide synthesis.

Four trityl-type (i.e. non-substituted trityl-, o-Cl-trityl-, o-F-trityl- and p-CN-trityl-) amidomethyl polystyrene resins were evaluated comparatively, in terms of the stability of the trityl-ester bond in slightly acidic dichloromethane solutions, and the p-CN-trityl-amidomethyl polystyrene resin was found to be the most stable of them.

Synthesis and angiogenetic activity in the chick chorioallantoic membrane model of thymosin beta-15.

Thymosin beta-15 (Tbeta15), a 44 amino acid peptide (MW = 5173) localized in human prostate and breast cancer tissues was successfully synthesized in multigram quantities using Fmoc solid-phase peptide synthesis. The synthesized product was shown to have the right structure by ESI and MALDI mass spectral techniques and amino acid analysis. Relatively high yield was achieved, which might be due to enhanced acid stability of the p-cyanotrityl resin used.

Investigation of the epitopic structure of thymosin beta10 by epitope mapping experiments.

We present here a study on the epitopic structure and the immunochemical characteristics of thymosin beta10 (Tbeta10), a 43 aminoacid peptide involved in important cellular mechanisms, by using the epitope mapping Multipin method. Octapeptides overlapping by one amino acid so as to represent the whole sequence of Tbeta10 were synthesized on polystyrene pins and screened, using an ELISA method, with a polyclonal antiserum raised against intact recombinant Tbeta10. The octapeptides were also tested with anti-peptide oligoclonal antisera raised against the synthetic fragments Tbeta10[1-16] and Tbeta10[31-43], with polyclonal antisera raised against natural thymosin gamma4 (Tbeta4) or thymosin beta9 (Tbeta9), and with anti-peptide oligoclonal antisera raised against various fragments of Tbeta4 (i.

Direct ELISA method for the specific determination of prothymosin alpha in human specimens.

An enzyme linked immunosorbent assay, specific for prothymosin alpha (ProT alpha) was developed using an antibody against the synthetic C-terminal peptide ProT alpha[101-109] and isolated bovine ProT alpha for the preparation of standard solutions and immunoplates. Due to the antibody used, the ELISA developed was capable of fully discriminating between ProT alpha, the naturally occuring and partially homologous peptide parathymosin alpha (ParaT alpha) and the peptide thymosin alpha1 (T alpha1), whose sequence is identical to the [1-28] sequence of ProT alpha, and its in vivo occurrence is under question. Moreover, due to its improved sensitivity, the ELISA was capable of directly determining ProT alpha concentration in human serum and tissue extracts, without any pretreatment of the samples.

Development of specific anti-thymosin beta 10 antipeptide antibodies for application in immunochemical techniques.

We present theoretical and experimental data necessary for raising specific antibodies for thymosin beta 10, a 43-amino acid residues peptide occurring in human tissues. We postulate that thymosin beta 10 contains three major antigenic determinants (residues 2-8, 17-25, and 35-41). For antibody development, we synthesized the N-terminal fragment thymosin beta 10(1-16) as well as the C-terminal fragments thymosin beta 10(31-43) and thymosin beta 10(38-43), due to their putative antigenic properties and minimal structural similarity with the homologous peptide thymosin beta 4, which also occurs in humans.

Steric requirements at position B12 for high biological activity in insulin.

The alpha-helix formed by the amino acid residues 9-19 of the B-chain of insulin is involved in the stabilization of its three-dimensional structure. We have shown that modification at positions B9, B10, B12, and B16 results in analogues possessing biological activities ranging from ca. 0.

Divergence of the in vitro biological activity and receptor binding affinity of a synthetic insulin analogue, [21-asparaginamide-A]insulin.

The [21-asparaginamide-A]insulin ([Asn-(NH2)21-A]insulin) was synthesized by the procedures developed in this laboratory to investigate the contribution of the C-terminal residue, asparagine, of the A chain to the biological activity and receptor binding affinity of insulin. Its secondary structure was investigated by circular dichroism studies. The biological behavior of this analogue was compared with that of insulin in in vitro and in vivo tests and in receptor binding assays.

[21-arginine-A] insulin: a biologically active analog.

An analog of sheep insulin which differs from the parent molecule in that the C-terminal amino acid residue of the A chain, asparagine, is replaced by arginine, has been synthesized and isolated in highly purified form. The [Arg21] A chain of sheep insulin was synthesized by the fragment condensation approach and isolated as the S-sulfonated derivative. Conversion of the latter into the sulfhydryl form and interaction with the S-sulfonated B chain of bovine (sheep) insulin yielded [Arg21-A] sheep insulin, which was purified by chromatography on a carboxymethylcellulose column with an exponential sodium chloride gradient.

Chemical synthesis of [des(tetrapeptide B27--30), Tyr(NH2)26-B] and [des(pentapeptide B26--30), Phe(NH2)25-B] bovine insulins.

Two analogs of bovine insulin, [des(tetrapeptide B27--30), Tyr(NH2)26-B] and [des(pentapeptide B26--30), Phe(NH2)25-B] insulin, which differ from the parent molecule in that the C-terminal tetrapeptide and pentapeptide sequences, respectively, from the B chain have been eliminated and the newly exposed residues are amidated, have been synthesized. The [des(tetrapeptide B27--30), Tyr(NH2)26-B] insulin shows potencies of 16.8 IU/mg by the mouse convulsion assay method and 10.