Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Characterization of [LeuB-24]- and [LeuB-25]-insulin analogues. Receptor binding and biological activity.

ABSTRACT: Human [LeuB-24]- and [LeuB-25]-insulins were semi-synthesized from porcine insulin by an enzyme-assisted coupling method. The receptor-binding ability of [LeuB-24]- and [LeuB-25]-insulins was 30--48% and 2--5% respectively of that of human insulin. There was no significant difference in degradation between human insulin and these analogues on incubation with isolated adipocytes. The decreased affinity of these analogues was due to an increased dissociation rate rather than a change in the association rate of their binding to human cultured lymphocytes. The negative co-operative effect of [LeuB-24]- and [LeuB-25]-insulin was decreased to 50 and 1% respectively of that of human insulin at a concentration of 100 ng/ml. The ability of [LeuB-24]- and [LeuB-25]-insulin to stimulate 2-deoxyglucose uptake in isolated rat adipocytes was 35 and 4% respectively of that of human insulin. These analogues did not have an antagonistic effect on the biological activity of human insulin. The immunoreactivity of [LeuB-25]insulin was similar to that of porcine or human insulin, whereas [LeuB-24]insulin demonstrated decreased binding to anti-(porcine insulin) antibodies. These findings suggest that B-chain phenylalanine-25 residue is more crucial for receptor binding and negative co-operativity, whereas the B-chain phenylalanine-24 residue may play a more important role in binding to anti-insulin antibody.

SUBMITTER: Kobayashi M

PROVIDER: S-EPMC1158628 | biostudies-other | 1982 Sep

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Metabolism and biological activity of 25-fluorocholecalciferol, 24-dehydrocholecalciferol and 25-dehydrocholecalciferol in the rat.

Project description:Three side-chain analogues of cholecalciferol (vitamin D3) modified at C-25, namely 25-fluorocholecalciferol, 24-dehydrocholecalciferol and 25-dehydrocholecalciferol, conceived as potential inhibitors of the cholecalciferol 25-hydroxylase have been prepared and tested in the rat. These compounds markedly diminish conversion in vivo of cholecalciferol into 25-hydroxycholecalciferol, but are not antagonists of vitamin D action, because they themselves possess significant biological activity in vivo. Each compound is capable of stimulating the intestinal transport of calcium and the mobilization of calcium from bone in vitamin D-deficient rats. Biological responses equivalent to those generated by a physiological dose of cholecalciferol (0.05 microgram) are produced, however, only when the analogues are administered at high doses (5-50 microgram). The biological activity of 24-dehydrocholecalciferol and 25-dehydrocholecalciferol is shown to result from conversion, in vivo, to the natural hormone, 1 alpha,25-dihydroxycholecalciferol, whereas 25-fluorocholecalciferol is metabolically activated in the rat by hydroxylation to 1 alpha-hydroxy-25-fluorocholecalciferol. This latter conversion is the first reported example of the 1 alpha-hydroxylation of a vitamin D compound lacking the 25-hydroxy group.

| S-EPMC1161227 | biostudies-other

Engineering of insulin receptor isoform-selective insulin analogues.

Project description:BACKGROUND: The insulin receptor (IR) exists in two isoforms, A and B, and the isoform expression pattern is tissue-specific. The C-terminus of the insulin B chain is important for receptor binding and has been shown to contact the IR just adjacent to the region where the A and B isoforms differ. The aim of this study was to investigate the importance of the C-terminus of the B chain in IR isoform binding in order to explore the possibility of engineering tissue-specific/liver-specific insulin analogues. METHODOLOGY/PRINCIPAL FINDINGS: Insulin analogue libraries were constructed by total amino acid scanning mutagenesis. The relative binding affinities for the A and B isoform of the IR were determined by competition assays using scintillation proximity assay technology. Structural information was obtained by X-ray crystallography. Introduction of B25A or B25N mutations resulted in analogues with a 2-fold preference for the B compared to the A isoform, whereas the opposite was observed with a B25Y substitution. An acidic amino acid residue at position B27 caused an additional 2-fold selective increase in affinity for the receptor B isoform for analogues bearing a B25N mutation. Furthermore, the combination of B25H with either B27D or B27E also resulted in B isoform-preferential analogues (2-fold preference) even though the corresponding single mutation analogues displayed no differences in relative isoform binding affinity. CONCLUSIONS/SIGNIFICANCE: We have discovered a new class of IR isoform-selective insulin analogues with 2-4-fold differences in relative binding affinities for either the A or the B isoform of the IR compared to human insulin. Our results demonstrate that a mutation at position B25 alone or in combination with a mutation at position B27 in the insulin molecule confers IR isoform selectivity. Isoform-preferential analogues may provide new opportunities for developing insulin analogues with improved clinical benefits.

| S-EPMC3098868 | biostudies-literature

Stereoselective Synthesis of 24-Fluoro-25-Hydroxyvitamin D3 Analogues and Their Stability to hCYP24A1-Dependent Catabolism.

Project description:Two 24-fluoro-25-hydroxyvitamin D3 analogues (3,4) were synthesized in a convergent manner. The introduction of a stereocenter to the vitamin D3 side-chain C24 position was achieved via Sharpless dihydroxylation, and a deoxyfluorination reaction was utilized for the fluorination step. Comparison between (24R)- and (24S)-24-fluoro-25-hydroxyvitamin D3 revealed that the C24-R-configuration isomer 4 was more resistant to CYP24A1-dependent metabolism than its 24S-isomer 3. The new synthetic route of the CYP24A1 main metabolite (24R)-24,25-dihydroxyvitamin D3 (6) and its 24S-isomer (5) was also studied using synthetic intermediates (30,31) in parallel.

| S-EPMC8584271 | biostudies-literature

Senolytic activity of piperlongumine analogues: Synthesis and biological evaluation.

Project description:Selective clearance of senescent cells (SCs) has emerged as a potential therapeutic approach for age-related diseases, as well as chemotherapy- and radiotherapy-induced adverse effects. Through a cell-based phenotypic screening approach, we recently identified piperlongumine (PL), a dietary natural product, as a novel senolytic agent, referring to small molecules that can selectively kill SCs over normal or non-senescent cells. In an effort to establish the structure-senolytic activity relationships of PL analogues, we performed a series of structural modifications on the trimethoxyphenyl and the α,β-unsaturated δ-valerolactam rings of PL. We show that modifications on the trimethoxyphenyl ring are well tolerated, while the Michael acceptor on the lactam ring is critical for the senolytic activity. Replacing the endocyclic C2-C3 olefin with an exocyclic methylene at C2 render PL analogues 47-49 with increased senolytic activity. These α-methylene containing analogues are also more potent than PL in inducing ROS production in WI-38 SCs. Similar to PL, 47-49 reduce the protein levels of oxidation resistance 1 (OXR1), an important oxidative stress response protein that regulates the expression of a variety of antioxidant enzymes, in cells. This study represents a useful starting point toward the discovery of senolytic agents for therapeutic uses.

| S-EPMC6087492 | biostudies-literature

Heteroatom analogues of hydrocodone: synthesis and biological activity.

Project description:Heteroatom analogues of hydrocodone, in which the N-methyl functionality was replaced with oxygen, sulfur, sulfoxide, and sulfone, were prepared by a short sequence from the ethylene glycol ketal of hydrocodone; a carbocyclic analogue of bisnorhydrocodone was also prepared. The compounds were tested for receptor binding and revealed moderate levels of activity for the sulfone analogue of hydrocodone.

| S-EPMC3618612 | biostudies-other

Rhodomycin analogues from Streptomyces purpurascens: isolation, characterization and biological activities.

Project description:During a screening program for bioactive natural products, a potential Streptomyces sp was isolated from soil. On the basis of biochemical, cultural, physiological and 16S rRNA gene analysis, it was identified as Streptomyces purpurascens. The isolate was grown in liquid medium and the crude antibiotic complex was obtained by ethyl acetate extraction. Seven purified fractions were obtained by preparative Thin Layer Chromatography (TLC). Acid hydrolysis of each fraction and subsequent TLC led to the identification of aglycones and sugars indicating these compounds to be Rhodomycin and its analogues. The identity of these compounds was established on the basis of UV-visible and FT-IR spectra and comparison with published data. The compounds were active against Gram-positive bacteria. Compound E, identified as Rhodomycin B, was found to be the most potent compound with an MIC of 2 ?g/ml against Bacillus subtilis. Compounds A and F identified as ?2-Rhodomycin II and Obelmycin respectively, and Compound E exhibited an IC50 of 8.8 ?g/ml against HeLa cell line but no cytotoxicity was found against L929.

| S-EPMC3667366 | biostudies-literature

Importance of each residue within secretin for receptor binding and biological activity.

Project description:Secretin is a linear 27-residue peptide hormone that stimulates pancreatic and biliary ductular bicarbonate and water secretion by acting at its family B G protein-coupled receptor. While, like other family members, the carboxyl-terminal region of secretin is most important for high affinity binding and its amino-terminal region is most important for receptor selectivity and receptor activation, determinants for these activities are distributed throughout the entire length of this peptide. In this work, we have systematically investigated changing each residue within secretin to alanine and evaluating the impact on receptor binding and biological activity. The residues most critical for receptor binding were His1, Asp3, Gly4, Phe6, Thr7, Ser8, Leu10, Asp15, Leu19, and Leu23. The residues most critical for biological activity included His1, Gly4, Thr7, Ser8, Glu9, Leu10, Leu19, Leu22, and Leu23, with Asp3, Phe6, Ser11, Leu13, Asp15, Leu26, and Val27 also contributing. While the importance of residues in positions analogous to His1, Asp3, Phe6, Thr7, and Leu23 is conserved for several closely related members of this family, Leu19 is uniquely important for secretin. We, therefore, have further studied this residue by molecular modeling and molecular dynamics simulations. Indeed, the molecular dynamics simulations showed that mutation of Leu19 to alanine was destabilizing, with this effect greater than that observed for the analogous position in the other close family members. This could reflect reduced contact with the receptor or an increase in the solvent-accessible surface area of the hydrophobic residues in the carboxyl terminus of secretin as bound to its receptor.

| S-EPMC3071462 | biostudies-literature

Milligram production and biological activity characterization of the human chemokine receptor CCR3.

Project description:Human chemokine receptor CCR3 (hCCR3) belongs to the G protein-coupled receptors (GPCRs) superfamily of membrane proteins and plays major roles in allergic diseases and angiogenesis. In order to study the structural and functional mechanism of hCCR3, it is essential to produce pure protein with biological functions on a milligram scale. Here we report the expression of hCCR3 gene in a tetracycline-inducible stable mammalian cell line. A cell clone with high hCCR3 expression was selected from 46 stably transfected cell clones and from this cell line pure hCCR3 on a milligram scale was obtained after two-step purification. Circular dichroism spectrum with a characteristic shape and magnitude for α-helix indicated proper folding of hCCR3 after purification. The biological activity of purified hCCR3 was verified by its high binding affinity with its endogenous ligands CCL11 and CCL24, with K D in the range of 10(-8) M to 10(-6) M.

| S-EPMC3670934 | biostudies-literature

Smenamide A Analogues. Synthesis and Biological Activity on Multiple Myeloma Cells.

Project description:Smenamides are an intriguing class of peptide/polyketide molecules of marine origin showing antiproliferative activity against lung cancer Calu-1 cells at nanomolar concentrations through a clear pro-apoptotic mechanism. To probe the role of the activity-determining structural features, the 16-epi-analogue of smenamide A and eight simplified analogues in the 16-epi series were prepared using a flexible synthetic route. The synthetic analogues were tested on multiple myeloma (MM) cell lines showing that the configuration at C-16 slightly affects the activity, since the 16-epi-derivative is still active at nanomolar concentrations. Interestingly, it was found that the truncated compound 8, mainly composed of the pyrrolinone terminus, was not active, while compound 13, essentially lacking the pyrrolinone moiety, was 1000-fold less active than the intact substance and was the most active among all the synthesized compounds.

| S-EPMC6025564 | biostudies-literature

Cyclic Biphalin Analogues Incorporating a Xylene Bridge: Synthesis, Characterization, and Biological Profile.

Project description:In this work we enhanced the ring lipophilicity of biphalin introducing a xylene moiety, thus obtaining three cyclic regioisomers. Novel compounds have similar in vitro activity as the parent compound, but one of these (6a) shows a remarkable increase of in vivo antinociceptive effect. Nociception tests have disclosed its significant high potency and the more prolonged effect in eliciting analgesia, higher than that of biphalin and of the disulfide-bridge-containing analogue (7).

| S-EPMC5554896 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data