| 7737114 |
NK-lysin, a novel effector peptide of cytotoxic T and NK cells. Structure and cDNA cloning of the porcine form, induction by interleukin 2, antibacterial and antitumour activity |
10.1002/j.1460-2075.1995.tb07150.x. |
EMBO J |
NK-lysin, a novel effector peptide of cytotoxic T and NK cells. Structure and cDNA cloning of the porcine form, induction by interleukin 2, antibacterial and antitumour activity
Abstract
- A 78 residue antimicrobial, basic peptide, NK-lysin, with three intrachain disulfide bonds was purified from pig small intestine and characterized. A corresponding clone was isolated from a porcine bone marrow cDNA library. The 780 bp DNA sequence had a reading frame of 129 amino acids which corresponded to NK-lysin. The clone was used to show that stimulation with human interleukin-2 induced synthesis of NK-lysin-specific mRNA in a lymphocyte fraction enriched for T and NK cells. Lower levels of mRNA were detected in tissues known to contain T and NK cells, such as small intestine, spleen and colon. Interleukin-2 also induced both proliferation of the lymphocyte fraction and cytolytic function in these cells. Immunostaining showed that NK-lysin was present in cells positive for CD8, CD2 and CD4. NK-lysin showed high anti-bacterial activity against Escherichia coli and Bacillus megaterium and moderate activity against Acinetobacter calcoaceticus and Streptococcus pyogenes. The peptide showed a marked lytic activity against an NK-sensitive mouse tumour cell line, YAC-1, but it did not lyse red blood cells. The amino acid sequence of NK-lysin exhibits 33% identity with a putative human preproprotein, NKG5, of unknown function but derived from a cDNA clone of activated NK cells. We suggest that NK-lysin is a new effector molecule of cytotoxic T and NK cells.
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| 7739904 |
Photoaffinity approaches to determining the sequence selectivities of DNA-small molecule interactions: actinomycin D and ethidium |
10.1093/nar/23.7.1252. |
Nucleic Acids Res |
Photoaffinity approaches to determining the sequence selectivities of DNA-small molecule interactions: actinomycin D and ethidium
Abstract
- The DNA photoaffinity ligands, 7-azidoactinomycin D and 8-azidoethidium, form DNA adducts that cause chain cleavage upon treatment with piperidine. Chemical DNA sequencing techniques were used to detect covalent binding. The relative preferences for modifications of all possible sites defined by a base pair step (e.g. GC) were determined within all quartet contexts such as (IGCJ). These preferences are described in terms of 'effective site occupations', which express the ability of a ligand to covalently modify some base in the binding site. Ideally, the effective site occupations measured for photoaffinity agents can also be related to site-specific, non-covalent association constants of the ligand. The sites most reactive with 7-azidoactinomycin D were those preferred for non-covalent binding of unsubstituted actinomycin D. GC sites were most reactive, but next-nearest neighbors exerted significant influences on reactivity. GC sites in 5'-(pyrimidine)GC(purine)-3' contexts, particularly TGCA, were most reactive, while reactivity was strongly suppressed for GC sites with a 5'-flanking G, or a 3'-flanking C. High reactivities were also observed for bases in the first (5') GG steps in TGGT, TGGG and TGGGT sequences recently shown to bind actinomycin D with high affinity. Pyrimidine-3',5'-purine steps and GG steps flanked by a T were most preferred by 8-azidoethidium, in agreement with the behavior of unsubstituted ethidium. The good correspondence between expected and observed covalent binding preferences of these two azide analogs demonstrates that photoaffinity labeling can identify highly preferred sites of non-covalent DNA binding by small molecules."
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| 7749913 |
Comparison of the solution structures of microcystin-LR and motuporin |
10.1038/nsb0295-114. |
Nat Struct Biol |
Comparison of the solution structures of microcystin-LR and motuporin
Abstract
- A comparison of the structures of two cyanobacterial toxins yields insights into how they may inhibit protein phosphatase-1 and -2A and why microcystins but not motuporin may covalently modify their protein phosphatase targets.
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| 7756452 |
Lysine vasopressin-induced increases in porcine myometrial contractility and intracellular Ca2+ concentrations of myometrial cells: involvement of oxytocin receptors |
10.1095/biolreprod52.3.584. |
Biol Reprod |
Lysine vasopressin-induced increases in porcine myometrial contractility and intracellular Ca2+ concentrations of myometrial cells: involvement of oxytocin receptors
Abstract
- The present study was undertaken to investigate whether lysine vasopressin (LVP) induces porcine myometrial contractions by activating vasopressin or oxytocin (OT) receptors. Both LVP (3 x 10(-9)-10(-6) M) and OT (3 x 10(-11)-10(-8) M) increased contractility dose-dependently in myometrium from both the luteal phase and prepartum period. Comparison of EC50s showed that OT was 75 and 57 times more potent than LVP in increasing myometrial contractility in pregnant and nonpregnant sows, respectively. L-366,948 (10(-8), 3 x 10(-8), 10(-7) M), a highly selective OT receptor antagonist, inhibited LVP- and OT-induced increases in myometrial contractility dose-dependently in both pregnant and nonpregnant tissues with similar antagonist affinity values (pA2). The V1 antagonist d(CH2)5D-Tyr(Me)2AVP also antagonized both LVP- and OT-induced increases in myometrial contractility, but higher concentrations (10(-7) and 10(-6) M) were required to achieve the antagonism. The V2 antagonist Aaa-D-Tyr(Et)-Phe-Val-Asn-Abu-Pro-Arg-Arg-NH2 (10(-6) M) did not alter this effect of LVP and OT. LVP (10(-9)-10(-6) M) and OT (10(-10)-10(-7) M) also increased intracellular Ca2+ (Ca2+i) concentrations in porcine myometrial cells from sows during the prepartum period in a dose-dependent manner, with OT being 14 times more potent than LVP. L-366,948 (10(-9)-3 x 10(-8) M) antagonized the effect of OT (10(-7) M) and LVP (10(-6) M) in a similar dose-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)
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| 7760068 |
Neosiphoniamolide A, a novel cyclodepsipeptide, with antifungal activity from the marine sponge Neosiphonia superstes |
10.1021/np50115a017. |
J Nat Prod |
Neosiphoniamolide A, a novel cyclodepsipeptide, with antifungal activity from the marine sponge Neosiphonia superstes
Abstract
- A novel cyclodepsipeptide, neosiphoniamolide A 1, has been isolated from the sponge Neosiphonia superstes. The structure of 1, which contains a 12-carbon hydroxy acid, glycine, valine, and a halogenated tyrosine residue in an 18-membered ring, is related to jaspamide and the geodiamolides, previously isolated from sponges. The structure was solved by spectroscopic analysis.
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| 7760751 |
Therapeutic application of matrix biology |
10.1016/0076-6879(94)45028-5. |
Methods Enzymol |
Therapeutic application of matrix biology
Abstract
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| 7763278 |
Ustiloxins, new antimitotic cyclic peptides: interaction with porcine brain tubulin |
10.1016/0006-2952(95)00072-8. |
Biochem Pharmacol |
Ustiloxins, new antimitotic cyclic peptides: interaction with porcine brain tubulin
Abstract
- Biochemical and electron microscopic studies demonstrated that ustiloxins A-D, which are antimitotic 13-membered cyclic peptides produced by the rice plant pathogen Ustilaginoidea virens, strongly inhibited the polymerization of porcine brain tubulin in vitro and depolymerized pre-formed microtubules. The IC50 values of polymerization inhibited by ustiloxins A-D were determined to be 0.7, 2.8, 4.4 and 6.6 microM, respectively, under the experimental conditions used, indicating that ustiloxin A is the most potent inhibitor of tubulin polymerization currently known. Ustiloxins A-C were found to inhibit the binding of radiolabelled rhizoxin to tubulin with inhibition constants (Ki) of 0.08, 0.13 and 0.23 microM, respectively, and also inhibited the binding of radiolabelled phomopsin A as strongly as rhizoxin. These results suggest that the binding site of ustiloxins is identical with that of rhizoxin.
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| 7763777 |
Structure of malformin B, a phytotoxic metabolite produced by Aspergillus niger |
10.1271/bbb.57.787. |
Biosci Biotechnol Biochem |
Structure of malformin B, a phytotoxic metabolite produced by Aspergillus niger
Abstract
- Malformin B, produced by Aspergillus niger, was separated into six compounds by HPLC. Their structures were determined by amino acid analyses, and by mass spectral and two-dimensional NMR experiments to be cyclic pentapeptides structurally related to malformin A1. Both the NMR and MS/MS experiments suggest cyclo-D-cysteinyl-D-cysteinyl-L-amino acid-D-amino acid-L-amino acid as the essential structure of malformins.
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| 7765754 |
Beauverolides L and La from Beauveria tenella and Paecilomyces fumosoroseus |
10.1016/s0031-9422(00)90402-3. |
Phytochemistry |
Beauverolides L and La from Beauveria tenella and Paecilomyces fumosoroseus
Abstract
- New beauverolides L and La were isolated and identified from the entomopathogenic fungi, Beauveria tenella and Paecilomyces fumosoroseus. Their structures, cyclo-3-hydroxy-4-methyldecanoyl-L-phenylalanyl-L-alanyl-D-leucyl , and cyclo-3-hydroxy-4-methyldecanoyl-L-phenylalanyl-L-alanyl-D-allo-i soleucyl were deduced from HPLC and GC-mass spectrometric analyses of their hydrolysates and NMR and mass spectral data.
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| 7765770 |
Construction of a new host-vector system in Arthrobacter sp. and cloning of the lipase gene |
10.1007/BF00902732. |
Appl Microbiol Biotechnol |
Construction of a new host-vector system in Arthrobacter sp. and cloning of the lipase gene
Abstract
- Arthrobacter sp. strain MIS38 was transformed with a shuttle vector containing the kanamycin resistant gene kan (derived from Tn5) by an electroporation method. This shuttle vector is from Brevibacterium lactofermentum and Escherichia coli, pULRS8. The following optimal condition of electroporation was determined. A square wave pulse of 1 kV/cm electric field strength for 0.5 ms duration yielded 3 x 10(5) transformants/micrograms plasmid DNA. The number of transformants increased with the amount of DNA over the range 0.01-5 micrograms. This host-vector system was then used successfully to clone and express a lipase gene from Arthrobacter sp. strain MIS38 into both Arthrobacter sp. MIS38 and E. coli JM109.
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| 7780308 |
Small cysteine-rich antifungal proteins from radish: their role in host defense |
10.1105/tpc.7.5.573. |
Plant Cell |
Small cysteine-rich antifungal proteins from radish: their role in host defense
Abstract
- Radish seeds have previously been shown to contain two homologous, 5-kD cysteine-rich proteins designated Raphanus sativus-antifungal protein 1 (Rs-AFP1) and Rs-AFP2, both of which exhibit potent antifungal activity in vitro. We now demonstrate that these proteins are located in the cell wall and occur predominantly in the outer cell layers lining different seed organs. Moreover, Rs-AFPs are preferentially released during seed germination after disruption of the seed coat. The amount of released proteins is sufficient to create a microenvironment around the seed in which fungal growth is suppressed. Both the cDNAs and the intron-containing genomic regions encoding the Rs-AFP preproteins were cloned. Transcripts (0.55 kb) hybridizing with an Rs-AFP1 cDNA-derived probe were present in near-mature and mature seeds. Such transcripts as well as the corresponding proteins were barely detectable in healthy uninfected leaves but accumulated systemically at high levels after localized fungal infection. The induced leaf proteins (designated Rs-AFP3 and Rs-AFP4) were purified and shown to be homologous to seed Rs-AFPs and to exert similar antifungal activity in vitro. A chimeric Rs-AFP2 gene under the control of the constitutive cauliflower mosaic virus 35S promoter conferred enhanced resistance to the foliar pathogen Alternaria longipes in transgenic tobacco. The term "plant defensins" is proposed to denote these defense-related proteins.
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| 7781985 |
A novel dodecadepsipeptide, cereulide, is an emetic toxin of Bacillus cereus |
10.1016/0378-1097(95)00119-P. |
FEMS Microbiol Lett |
A novel dodecadepsipeptide, cereulide, is an emetic toxin of Bacillus cereus
Abstract
- A vacuole-formation substance, cereulide of Bacillus cereus, is an emetic toxin in animals. Both oral administration and intraperitoneal injection of cereulide caused dose-dependent emesis in Suncus murinus, a new animal model of emesis. Vagotomy or a 5-HT3 receptor antagonist completely abolished this emetic effect. Therefore, cereulide causes emesis through the 5-HT3 receptor and stimulation of the vagus afferent. We also found that our purified cereulide caused swelling of mitochondria of HEp-2 cells.
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| 7787424 |
High-resolution solution structure of siamycin II: novel amphipathic character of a 21-residue peptide that inhibits HIV fusion |
10.1007/BF00211754. |
J Biomol NMR |
High-resolution solution structure of siamycin II: novel amphipathic character of a 21-residue peptide that inhibits HIV fusion
Abstract
- The 21-amino acid peptides siamycin II (BMY-29303) and siamycin I (BMY-29304), derived from Streptomyces strains AA3891 and AA6532, respectively, have been found to inhibit HIV-1 fusion and viral replication in cell culture. The primary sequence of siamycin II is CLGIGSCNDFAGCGYAIVCFW. Siamycin I differs by only one amino acid; it has a valine residue at position 4. In both peptides, disulfide bonds link Cys1 with Cys13 and Cys7 with Cys19, and the side chain of Asp9 forms an amide bond with the N-terminus. Siamycin II, when dissolved in a 50:50 mixture of DMSO and H2O, yields NOESY spectra with exceptional numbers of cross peaks for a peptide of this size. We have used 335 NOE distance constraints and 13 dihedral angle constraints to generate an ensemble of 30 siamycin II structures; these have average backbone atom and all heavy atom rmsd values to the mean coordinates of 0.24 and 0.52 A, respectively. The peptide displays an unusual wedge-shaped structure, with one face being predominantly hydrophobic and the other being predominantly hydrophilic. Chemical shift and NOE data show that the siamycin I structure is essentially identical to siamycin II. These peptides may act by preventing oligomerization of the HIV transmembrane glycoprotein gp41, or by interfering with interactions between gp41 and the envelope glycoprotein gp120, the cell membrane or membrane-bound proteins Frèchet, D. et al. (1994) Biochemistry, 33, 42-50. The amphipathic nature of siamycin II and siamycin I suggests that a polar (or apolar) site on the target protein may be masked by the apolar (or polar) face of the peptide upon peptide/protein complexation.
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| 7788905 |
Role of endothelin-1 in beagles with dehydromonocrotaline-induced pulmonary hypertension |
10.1161/01.cir.92.1.114. |
Circulation |
Role of endothelin-1 in beagles with dehydromonocrotaline-induced pulmonary hypertension
Abstract
- Although plasma levels of endothelin-1 (ET-1) increase in patients with pulmonary hypertension (PH), its role in PH is unknown. We investigated the contribution of endogenous ET-1 to cardiopulmonary changes in beagles with dehydromonocrotaline (DMCT)-induced PH.\n \n \n \n \n Eight 3-month-old beagles were given a single injection of 3 mg/kg DMCT via the right atrium. During the 8 weeks after injection, the mean pulmonary arterial pressure (PAP) and plasma ET-1 level increased significantly from 11.6 +/- 2.3 to 35.9 +/- 7.1 mm Hg and from 1.24 +/- 0.25 to 3.25 +/- 0.94 pg/mL, respectively. In controls, ET-1 infusion elevated the systemic arterial pressure (SAP) but did not alter PAP. In PH beagles, ET-1 infusion increased SAP, which was attenuated by FR139317 (an endothelin type ET A receptor antagonist), and produced a dose-dependent decrease in PAP, which was attenuated by RES-701-1 (an ETB receptor antagonist). In PH beagles, FR139317 infusion decreased PAP, and RES-701-1 infusion increased PAP. Sarafotoxin S6c (an ETB agonist) infusion decreased PAP in PH beagles.\n \n \n \n \n These results suggest that endogenous ET-1 is elevated in PH disease and may mitigate PH by acting on ETB receptors.
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| 7790842 |
Effects of annetocin, an oxytocin-related peptide isolated from the earthworm Eisenia foetida, and some putative neurotransmitters on gut motility of the earthworm |
10.1002/jez.1402720303. |
J Exp Zool |
Effects of annetocin, an oxytocin-related peptide isolated from the earthworm Eisenia foetida, and some putative neurotransmitters on gut motility of the earthworm
Abstract
- Annetocin, an oxytocin-related peptide recently isolated from the lumbricid earthworm Eisenia foetida, and putative transmitter substances were examined for their effects on rhythmic, spontaneous contractions of isolated gut preparations of the earthworm. Significant, dose-dependent effects of the following substances were observed: acetylcholine (ACh), gamma-aminobutyric acid (GABA), and dopamine were excitatory, while serotonin (5-HT) and octopamine were inhibitory. Annetocin, oxytocin, and vasotocin stimulated spontaneous contraction of the earthworm gut, annetocin being approximately 10-fold more potent than oxytocin or vasotocin. However, arginine-vasopressin (Arg-vasopressin), lysine-vasopressin (Lys-vasopressin), tocinoic acid (N-terminal hexapeptide fragment of oxytocin), and MSH release-inhibiting factor (MIF; C-terminal tripeptide fragment of oxytocin) did not show any effect on the earthworm gut motility. On the other hand, oxytocin, vasotocin, Arg-vasopressin, Lys-vasopressin, and tocinoic acid caused spontaneous contractions of isolated rat uterine preparations, where the potency was in this order, while annetocin and MIF exerted no oxytocic activity on the uterus. Dose-response relationship of the effects of annetocin and its related peptides on the annelid and mammalian systems shows that amino acid residue at the third position of these peptides is important for exertion of excitatory action on the smooth muscle systems. The results in the present study suggest that receptors for annetocin and for GABA on the earthworm gut, unlike those for ACh, desensitize during continuous exposure to these substances.
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