| 8557598 |
YM-47141 and 47142, new elastase inhibitors produced by Flexibacter sp. Q17897. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities |
10.7164/antibiotics.48.1425. |
J Antibiot (Tokyo) |
YM-47141 and 47142, new elastase inhibitors produced by Flexibacter sp. Q17897. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities
Abstract
- In the course of our screening for elastase inhibitors from microorganism, we have found two new cyclic-depsipeptides designated YM-47141 and 47142. In this paper, we described the taxonomy of the producing organism and isolation, physico-chemical properties, and biological activities of YM-47141 and 47142.
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| 8557599 |
YM-47141 and YM-47142, new elastase inhibitors produced by Flexibacter sp. Q17897. II. Structure elucidation |
10.7164/antibiotics.48.1430. |
J Antibiot (Tokyo) |
YM-47141 and YM-47142, new elastase inhibitors produced by Flexibacter sp. Q17897. II. Structure elucidation
Abstract
- YM-47141 and YM-47142 are new elastase inhibitor produced by Flexibacter sp. Q17897. These structures were elucidated by MS and NMR spectral analysis. YM-47141 and YM-47142 were the cyclic peptides containing tricarbonyl moiety hydrated on the center carbonyl carbon in DMSO-d6.
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| 8557614 |
Siamycins I and II, new anti-HIV-1 peptides: II. Sequence analysis and structure determination of siamycin I |
10.7164/antibiotics.48.1515. |
J Antibiot (Tokyo) |
Siamycins I and II, new anti-HIV-1 peptides: II. Sequence analysis and structure determination of siamycin I
Abstract
|
| 8564928 |
The antitumoral compound Kahalalide F acts on cell lysosomes |
10.1016/0304-3835(95)04036-6. |
Cancer Lett |
The antitumoral compound Kahalalide F acts on cell lysosomes
Abstract
- The target for the antitumoral peptidic drug, Kahalalide F, has been studied in cultured cells. In the presence of the compound, the cells became impressively swollen, showing the formation of large vacuoles. The formation of these vacuoles appears to be the consequence of changes in lysosomal membranes. Thus, lysosomes are a target for Kahalalide F action.
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| 8566232 |
The 3D-structure of a natural inhibitor of cell adhesion molecule expression |
10.1016/0014-5793(95)01453-5. |
FEBS Lett |
The 3D-structure of a natural inhibitor of cell adhesion molecule expression
Abstract
- The three-dimensional structure of cyclopeptolide HUN-7293, a naturally-occurring inhibitor of cell adhesion molecule expression, has been determined from nuclear magnetic resonance data recorded in solution and from X-ray diffraction analysis of single crystals. The backbone conformation of HUN-7293 is characterized by two cis-peptide bonds in both the solution and crystalline state. Differences between the solution and crystal structure are visible for the orientation of some side chains and the strength of two transannular hydrogen bonds. Such structural information helps to provide insight into the molecular architecture of HUN-7293 on the atomic level and opens the way for structure-based modifications of this novel inhibitor of cell adhesion molecule expression.
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| 8577744 |
Structure-activity analysis of thanatin, a 21-residue inducible insect defense peptide with sequence homology to frog skin antimicrobial peptides |
10.1073/pnas.93.3.1221. |
Proc Natl Acad Sci U S A |
Structure-activity analysis of thanatin, a 21-residue inducible insect defense peptide with sequence homology to frog skin antimicrobial peptides
Abstract
- Immune challenge to the insect Podisus maculiventris induces synthesis of a 21-residue peptide with sequence homology to frog skin antimicrobial peptides of the brevinin family. The insect and frog peptides have in common a C-terminally located disulfide bridge delineating a cationic loop. The peptide is bactericidal and fungicidal, exhibiting the largest antimicrobial spectrum observed so far for an insect defense peptide. An all-D-enantiomer is nearly inactive against Gram-negative bacteria and some Gram-positive strains but is fully active against fungi and other Gram-positive bacteria, suggesting that more than one mechanism accounts for the antimicrobial activity of this peptide. Studies with truncated synthetic isoforms underline the role of the C-terminal loop and flanking residues for the activity of this molecule for which we propose the name thanatin.
|
| 8585111 |
Measurement of AM19 and other cyclosporine metabolites in the blood of liver transplant patients with stable liver function |
10.1097/00007691-199510000-00008. |
Ther Drug Monit |
Measurement of AM19 and other cyclosporine metabolites in the blood of liver transplant patients with stable liver function
Abstract
- Chronic renal impairment represents on of the major side effects of cyclosporine (CsA) immunotherapy for organ transplantation. The clinical relevance of selective measurement of CsA metabolites to correlating nephrotoxic activities remains inconclusive. A relatively simple and reliable method was developed to measure AM19 and four other CsA metabolites in whole blood by sequential solid-phase extraction and reversed phase high-pressure liquid chromatography (HPLC). The procedures were modified from a well-established method developed to quantitate CsA, the most important difference being in the elution step. The use of acetonitrile/methanol instead of ethylacetate/isopropanol in the elution procedure enhanced the absolute recoveries of metabolites. The washing steps were also slightly modified to recover AM19 quantitatively and specifically. Isocratic chromatographic conditions allowed very good separation of AM19, AM1, AM9, AM1c, AM4N, CsA, and the internal standard, cyclosporin C (CsC). Analytical recoveries for CsA and five of its metabolites ranged from 82 to 92%. No interfering substance from the matrix was found. The detection limit was 10 micrograms/l. The objectives of this study were to measure trough concentration of AM19 in whole blood, expressed as percentage of total metabolites plus parent CsA, and to determine if the blood level of AM19 could be used to predict subsequent changes in serum creatinine level in liver transplant patients. Twenty-three patients, who underwent liver transplantation between January and June 1993 were studied. Trough concentration of CsA in whole blood, serum creatinine and liver enzymes were constantly monitored. AM19 level was determined 5-8 months after transplantation. Preliminary results suggest an inverse relationship between AM19 and serum creatine levels.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 8590312 |
Neuropeptide regulation of cytokine expression: effects of VIP and Ro 25-1553 |
10.1089/jir.1995.15.993. |
J Interferon Cytokine Res |
Neuropeptide regulation of cytokine expression: effects of VIP and Ro 25-1553
Abstract
- The neuropeptide VIP is present in high concentrations in normal lung, where it acts as a potent bronchodilator. VIP also downregulates T lymphocyte proliferation, possibly through its effect on cytokine expression. Although deficiencies in VIP levels are associated with asthma, VIP replacement therapy is impaired by its rapid degradation in the pulmonary microenvironment. A metabolically stable VIP peptide analog Ro 25-1553 has been developed and shown to act as a potent smooth muscle relaxant and suppressant of inflammatory cell accumulation. Proinflammatory cytokines play essential roles in inflammatory reactions. Here we compare the effects of VIP and Ro 25-1553 on IL-2, IL-4, and IFN-gamma production. Both VIP and Ro 25-1553 inhibit IL-2 and IL-4 but not IFN-gamma production and induce intracellular cAMP. Similar to VIP, Ro 25-1553 downregulates the IL-2 message and affects IL-4 production posttranscriptionally. Cytokines play important roles in allergic reactions, and increased cytokine levels are present in allergic asthmatic subjects. Therefore, downregulation of IL-2 and IL-4 production by Ro 25-1553 could play a significant role in the antiinflammatory activity of this peptide within the pulmonary microenvironment.
|
| 8596242 |
Researchers look forward to sea granting gifts |
None |
JAMA |
Researchers look forward to sea granting gifts
Abstract
|
| 8601458 |
Structure of fuscopeptins, phytotoxic metabolites of Pseudomonas fuscovaginae |
10.1016/0014-5793(96)00043-9. |
FEBS Lett |
Structure of fuscopeptins, phytotoxic metabolites of Pseudomonas fuscovaginae
Abstract
- The structure of the fuscopeptins, bioactive lipodepsipeptides produced in culture by the gramineae pathogen Pseudomonas fuscovaginae, has been determined. The combined use of FAB mass spectroscopy NMR spectroscopy and chemical and enzymatic procedures allowed one to define a peptide moiety corresponding to Z-Dhb-D-Pro-L-Leu-D-Ala-D-Ala-D-Ala-D-Ala-D-Val-Gly-D-Ala-D-Val-D-Ala-D- Val-Z-Dhb-Da-Thr-L-Ala-L-Dab-D-Dab-L-Phe with the terminal carboxyl group closing a macrocyclic ring on the hydroxyl group of the allothreonine residue. The N-terminus is in turn acylated by 3-hydroxyoctanoate in fuscopeptin A and 3-hydroxydecanoate in fuscopeptin B. Some preliminary data on the biological activity of fuscopeptins are also reported.
|
| 8602529 |
A mammalian histone deacetylase related to the yeast transcriptional regulator Rpd3p. |
10.1126/science.272.5260.408 |
Science |
A mammalian histone deacetylase related to the yeast transcriptional regulator Rpd3p.
Abstract
- Trapoxin is a microbially derived cyclotetrapeptide that inhibits histone deacetylation in vivo and causes mammalian cells to arrest in the cell cycle. A trapoxin affinity matrix was used to isolate two nuclear proteins that copurified with histone deacetylase activity. Both proteins were identified by peptide microsequencing, and a complementary DNA encoding the histone deacetylase catalytic subunit (HD1) was cloned from a human Jurkat T cell library. As the predicted protein is very similar to the yeast transcriptional regulator Rpd3p, these
Results support a role for histone deacetylase as a key regulator of eukaryotic transcription.
|
| 8605253 |
Cell line-specific transcriptional activation of the promoter of the human guanylyl cyclase C/heat-stable enterotoxin receptor gene. |
10.1016/0167-4781(95)00190-5 |
Biochim. Biophys. |
Cell line-specific transcriptional activation of the promoter of the human guanylyl cyclase C/heat-stable enterotoxin receptor gene.
Abstract
- The guanylyl cyclase C protein, expressed primarily in the intestine, is the receptor for the heat-stable enterotoxin of Escherichia coli. We have isolated and sequenced the promoter region and the first exon of human guanylyl cyclase C and determined the major site of transcription initiation. Transfection of a -1973/+124 promoter/luciferase gene fusion construct in the Caco-2 intestinal cell line resulted in a high level of expression;
Results with deletion constructs indicate the presence of multiple positive-acting sequence elements. These promoter elements were not active upon transfection into NIH/3T3 and LLC-PK1 cell lines which do not express GC-C.
|
| 8609084 |
Isolation of plactins A, B, C and D, novel cyclic pentapeptides that stimulate cellular fibrinolytic activity |
10.7164/antibiotics.49.45. |
J Antibiot (Tokyo) |
Isolation of plactins A, B, C and D, novel cyclic pentapeptides that stimulate cellular fibrinolytic activity
Abstract
- Four novel cyclic pentapeptides, designated plactins A, B, C and D, were isolated by solvent extraction and reverse-phase HPLC from mycelium of a fungal strain F165 that belongs to the order of Agonomycetales. By a combination of chemical and spectroscopic analyses and chemical synthesis, the structures of plactins A, B, C and D were determined to be cyclo(-D-Val-L-Leu-D-alloIle-L-Try-D-Arg-), cyclo(-D-Val-L-Leu-D-Leu-L-Tyr-D-Arg-), cyclo(-D-Val-L-Leu-D-alloIle-L-Phe-D-Arg-) and cyclo(-D-Val-L-Leu-D-Leu-L-Phe-D-Arg-), respectively. Plactins stimulated U937 cell-mediated degradation of 125I-fibrin plates by 50% at a concentration of 7.5 approximately 32 microM.
|
| 8609091 |
A novel chitinase inhibitor from a marine bacterium, Pseudomonas sp |
10.7164/antibiotics.49.76. |
J Antibiot (Tokyo) |
A novel chitinase inhibitor from a marine bacterium, Pseudomonas sp
Abstract
- A new chitinase inhibitor, CI-4, was isolated from the culture broth of a marine bacterium Pseudomonas sp. IZ208. The structure of CI-4 was determined to be cyclo(L-Arg-D-Pro) by spectral studies and comparison with a synthetic sample. CI-4 showed inhibitory activity against chitinase.
|
| 8616710 |
Subcutaneous injection of a cyclic peptide antagonist of vitronectin receptor-type integrins inhibits retinal neovascularization |
10.1038/nm0596-529. |
Nat Med |
Subcutaneous injection of a cyclic peptide antagonist of vitronectin receptor-type integrins inhibits retinal neovascularization
Abstract
- Retinal neovascularization is a major cause of blindness in such disorders as retinopathy of prematurity, proliferative diabetic retinopathy and senile macular degeneration. Because ligation of vitronectin receptor-type integrins appears to be required for the survival and maturation of newly formed but not quiescent blood vessels in several vascular beds including the retina, blockade of this downstream adhesion receptor system was investigated. In a mouse model of hypoxia-induced retinal neovascularization twice daily administration of 1 to 20 mg cyclic alpha v-integrin antagonist peptide per kilogram of body weight reduced capillary proliferation in a dose-dependent fashion--maximum 76%--without obvious side effects. A cyclic control peptide displayed no inhibitory effect on neovascularization. These findings indicate that systemic application of vitronectin receptor antagonists appears to be clinically feasible and is efficient in preventing retinal neovascularization and superior to cytokine-blocking strategies.
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