Peptide research最新文献_第3页

Production of radiolabeled neuropeptide precursors by in vitro transcription and translation. 通过体外转录和翻译产生放射性标记神经肽前体。

Peptide research Pub Date : 1996-07-01

V Y Hook, M R Schiller, C Nguyen, S Yasothornsrikul

{"title":"Production of radiolabeled neuropeptide precursors by in vitro transcription and translation.","authors":"V Y Hook, M R Schiller, C Nguyen, S Yasothornsrikul","doi":"","DOIUrl":"","url":null,"abstract":"Bioactive peptide hormones and neurotransmitters are required for neuroendocrine regulation of cellular functions. Importantly, proteolytic processing of inactive neuropeptide precursors is required to generate physiologically active peptide hormones and neurotransmitters. Studies of the processing enzymes require authentic neuropeptide precursors as substrates, rather than peptide substrates. This study demonstrates an efficient method to general 35S-precursors from cloned cDNAs by in vitro transcription and translation. In vitro transcription of neuropeptide cDNAs with SP6 RNA polymerase generates large amounts (micrograms) of corresponding RNAs. Subsequent in vitro translation of RNAs with wheat germ extract and 35S-methionine generates large quantities of 35S-precursors (10-25 million cpm 35S-precursor protein per reaction) with high specific radioactivity. The radiolabeled precursor substrates offer a reliable, sensitive and accurate method for detecting the proteolytic activity. Importantly, specific detection of the primary proenkephalin processing activity in chromaffin granules by 35S-enkephalin precursor as substrate, but not by peptide methylcoumarinamide (MCA) substrates, illustrates the significance of using full-length precursor to detect appropriate processing enzymes. This study demonstrates that efficient production of radiolabeled neuropeptide precursors by in vitro transcription and translation will be useful for in vitro assays of relevant processing proteases.","PeriodicalId":20005,"journal":{"name":"Peptide research","volume":"9 4","pages":"183-7"},"PeriodicalIF":0.0,"publicationDate":"1996-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19877905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

D-amino acid substitution of residues 32 to 46 of the glycoprotein hormone common alpha-subunit: development of a synthetic glycoprotein hormone antagonist. 糖蛋白激素共同α -亚基32 - 46残基的d -氨基酸取代:合成糖蛋白激素拮抗剂的研制。

Peptide research Pub Date : 1996-07-01

N Leng, P Grasso, L E Reichert

{"title":"D-amino acid substitution of residues 32 to 46 of the glycoprotein hormone common alpha-subunit: development of a synthetic glycoprotein hormone antagonist.","authors":"N Leng, P Grasso, L E Reichert","doi":"","DOIUrl":"","url":null,"abstract":"We have used single- or double-point D-amino acid substitutions to study the structure-function relationships involving residues 32 to 46 of the glycoprotein hormone common alpha-subunit (GPHa) and the testicular follicle-stimulating hormone (FSH) and luteinizing hormone (LH/hCG) receptors. D-Amino acid substitution analogs of GPHa(32-46) were synthesized and tested in both FSH and hCG radioligand receptor assays using bovine calf testis membranes as receptor source. Correct orientation of the amino acid side chains was generally of paramount importance for peptide interaction with receptor and bioactivity. Most substitutions with corresponding D-amino acids did not enhance the potency of native GPHa(32-46). A significant increment in peptide potency, however, was observed by inversion of configuration at positions Ser-34 and Thr-39 with D-amino acid isoforms. Based on the relative potency of each peptide analog. [D-Ser-34, D-Thr-39]GPHa(32-46) was approximately twofold more potent than native peptide GPHa(32-46) in both FSH and hCG radioligand receptor assays. [D-Ser-34, D-Thr-39]GPHa(32-46) also markedly inhibited FSH-stimulated estradiol biosynthesis in cultured rat Sertoli cells. The present study is unique in that it represents the first report of utilizing D-amino acid substitution to develop more potent peptide analogs related to the glycoprotein hormone common alpha-subunit region 32-46. Our results offer hope for the development of more potent and stabile peptide antagonists of possible usefulness in fertility regulation and control.","PeriodicalId":20005,"journal":{"name":"Peptide research","volume":"9 4","pages":"188-94"},"PeriodicalIF":0.0,"publicationDate":"1996-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19877906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Studies on the delineation of the hormone-specific antigenic determinants of human follicle-stimulating hormone. 人类促卵泡激素的激素特异性抗原决定因子的研究。

Peptide research Pub Date : 1996-07-01

D Lal, S D Mahale, K S Iyer

引用次数: 0

Sandostatin labeled with 99mTc: in vitro stability, in vivo validity and comparison with 111In-DTPA-octreotide. 99mTc标记的山多他汀体外稳定性、体内效度及与111in - dtpa -奥曲肽的比较

Peptide research Pub Date : 1996-05-01

H Kolan, J Li, M L Thakur

{"title":"Sandostatin labeled with 99mTc: in vitro stability, in vivo validity and comparison with 111In-DTPA-octreotide.","authors":"H Kolan, J Li, M L Thakur","doi":"","DOIUrl":"","url":null,"abstract":"Sandostatin, a synthetic octapeptide analog of a native hormone somatostatin, was labeled with a commonly available, inexpensive radionuclide, 99mTc, and evaluated for its suitability for in vivo imaging. Labeling was accomplished by reduction of the cystine bridge, which provided two sulfhydryl groups for chelation with 99mTc. The complex was examined for thermodynamic stability in vitro and in experimental animals. Receptor specificity of the complex was determined using rat brain cortex membrane rich in somatostatin receptors, and its tissue distribution was studied in nude mice bearing human prostate cancer. In these studies, 99mTc-labeled oxytocin, a nonspecific peptide with similar molecular weight, served as a control and 111In-DTPA-octreotide served as a standard. The labeling method was simple, did not require protecting and deprotecting functional groups and yields were high (ca. 70%). The in vitro and in vivo stability was excellent, and Kd values were in the nanomolar range, similar to those of 111In-DTPA-octreotide. At 24 hours post-injection, the tumor uptake for 99mTc-Sandostatin, expressed as percent of injected dose per gram (% ID/g), was higher, but the tumor/blood and tumor/muscle ratios were lower than those for 111In-DTPA-octreotide. This agent, with its improved target-to-nontarget ratios, should prove to be of value for imaging somatostatin receptor-positive tumors.","PeriodicalId":20005,"journal":{"name":"Peptide research","volume":"9 3","pages":"144-50"},"PeriodicalIF":0.0,"publicationDate":"1996-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19840037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparison of the immune response elicited by a free peptide and a lipopeptide construct. 游离肽和脂肽结构引起的免疫反应的比较。

Peptide research Pub Date : 1996-05-01

I Ferru, C Rollin, J Estaquier, P Sutton, M Delacre, A Tartar, H Gras-Masse, C Auriault

{"title":"Comparison of the immune response elicited by a free peptide and a lipopeptide construct.","authors":"I Ferru, C Rollin, J Estaquier, P Sutton, M Delacre, A Tartar, H Gras-Masse, C Auriault","doi":"","DOIUrl":"","url":null,"abstract":"Among the synthetic peptides derived from the 28-kDa Schistosoma mansoni gluthatione-S-transferase (Sm28GST), the C-terminal peptide, comprising amino acid residues 190 to 211, represents a major T-cell epitope in both infected humans and Sm28GST-immunized mice. The aim of this study was to determine the nature of the immune response induced by the 190-211 peptide coupled to a fatty acid (lipopeptide construction) in comparison to the free form. We explored B- and T-cell responses elicited by these two peptidic constructions in three different mouse strains (BALB/c, CBA/N and C57B1/6). For all strains, the addition of a lipid chain to the 190-211 peptide greatly modified its immunogenicity. The lipopeptide, compared to the free form, induced a greatly reduced antibody response against the peptide, whereas the production of messenger for cytokines was greatly increased after immunization with the lipopeptide. Immunization with peptide led mainly to a Th1-type cytokine profile following antigenic restimulation in vitro, while lipopeptide, in general, induced a mixed profile, and that occurred most significantly with the production of messengers for the protective cytokines IFN-gamma and IL-2, even without antigenic restimulations. This modification of immunogenicity of a peptide by the addition of a lipid chain could be of value in the development of efficient peptide vaccines.","PeriodicalId":20005,"journal":{"name":"Peptide research","volume":"9 3","pages":"136-43"},"PeriodicalIF":0.0,"publicationDate":"1996-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19840034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tandem use of PCR and synthetic peptides to map helper T-cell epitopes on 27-kDa sexual stage antigen of Plasmodium falciparum. 利用PCR和合成肽串联定位恶性疟原虫性期抗原27-kDa辅助t细胞表位。

Peptide research Pub Date : 1996-05-01

G K Koski, I N Ploton, R Viscidi, N Kumar

{"title":"Tandem use of PCR and synthetic peptides to map helper T-cell epitopes on 27-kDa sexual stage antigen of Plasmodium falciparum.","authors":"G K Koski, I N Ploton, R Viscidi, N Kumar","doi":"","DOIUrl":"","url":null,"abstract":"Monoclonal antibodies recognizing two overlapping linear epitopes (amino acid residues 10 to 25) on the 27-kDa sexual stage antigen of Plasmodium falciparum (Pfg 27) effectively reduce the infectivity of the parasites to mosquitoes. Although malaria transmission-blocking immunity is largely antibody-mediated, T cells play critical roles in the regulation of antibody-secreting B cells. In order to facilitate the development of a malaria transmission-blocking subunit vaccine, studies were undertaken to map epitopes on Pfg 27 recognized by T-helper lymphocytes. Pfg27-specific T-cell hybridoma clones were produced from rPfg27-immunized BALB/c (H-2d) and C57BL/6 (H-2b) mice, and used in studies to map antigenic determinants using PCR-generated Pfg27 gene fragments expressed in E. coli and synthetic peptides based on the Pfg27 sequence. We identified and mapped five distinct T-cell epitopes that are recognized by major histocompatibility complex (MHC) class II-restricted T-cell hybridoma clones. A single peptide (21 residues) was shown to contain two tandem or partially overlapping epitopes recognized by T-cell hybridomas in the context of I-Ad and I-Ab, respectively. Synthetic peptides representing epitopes recognized by T-cell hybridoma clones elicited strong IgG responses in immunized mice, suggesting that T-cells of the helper phenotype were stimulated in vivo by these peptides. These studies represent the first detailed T-cell epitope analysis of a malaria sexual-stage antigen.","PeriodicalId":20005,"journal":{"name":"Peptide research","volume":"9 3","pages":"127-35"},"PeriodicalIF":0.0,"publicationDate":"1996-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19840733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improved performances of spot multiple peptide synthesis. 改进了现场多肽合成的性能。

Peptide research Pub Date : 1996-05-01

F Molina, D Laune, C Gougat, B Pau, C Granier

引用次数: 0

Syntheses and biological activities of parallel and antiparallel homo and hetero bis-cystine dimers of oxytocin and deamino-oxytocin. 后叶催产素和去氨基后叶催产素平行和反平行同异双胱氨酸二聚体的合成及其生物学活性。

Peptide research Pub Date : 1996-05-01

L Chen, H Bauerová, J Slaninová, G Barany

{"title":"Syntheses and biological activities of parallel and antiparallel homo and hetero bis-cystine dimers of oxytocin and deamino-oxytocin.","authors":"L Chen, H Bauerová, J Slaninová, G Barany","doi":"","DOIUrl":"","url":null,"abstract":"New methods have been developed for the synthesis of disulfide-bridged homo and hetero peptide dimers (both parallel and antiparallel), as exemplified in the oxytocin and deamino-oxytocin families. The linear sequences were assembled by 9-fluorenyl-methyloxycarbonyl (Fmoc) solid-phase synthesis techniques, with orthogonal protection for the two beta-thiols by appropriate combinations of S-[(N'-methyl-N'-phenylcarbamoyl)sulfernyl] (Snm), S-acetamido-methyl (Acm) and S-2, 4, 6-trimethoxybenzyl (Tmob) groups. Two octapeptide-resins gave rise to four different nonapeptide amides, which were brought together in defined ways to provide access to four of the six possible dimeric products. For each dimer, the first disulfide bond was formed in solution by a directed method, and then the second disulfide bond was formed, without purification of the intermediates, by iodine oxidation. Final isolated yields of the desired pure dimers were in the 20% to 40% range. Biological activities ranged from 0.2% to 6% that of oxytocin, depending on the assay, and were in some cases considerably protracted. These data are consistent with the hypothesis that dimers revert slowly to monomers under the testing conditions.","PeriodicalId":20005,"journal":{"name":"Peptide research","volume":"9 3","pages":"114-21"},"PeriodicalIF":0.0,"publicationDate":"1996-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19840729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mass spectrometric sequencing of synthetic peptides containing alpha, alpha-dialkylated amino acid residues by MALDI post-source decay analysis. 利用MALDI源后衰减分析对含有α， α -二烷基化氨基酸残基的合成肽进行质谱测序。

Peptide research Pub Date : 1996-05-01

H Wenschuh, D Suckau, U Rapp, M Bienert, F Krause

引用次数: 0

Optimized preparation of deca(L-alanyl)-L-valinamide by 9-fluorenylmethyloxycarbonyl (Fmoc) solid-phase synthesis on polyethylene glycol-polystyrene (PEG-PS) graft supports, with 1,8-diazobicyclo [5.4.0]-undec-7-ene (DBU) deprotection. 在1,8-重氮双环[5.4.0]-十一-7-烯(DBU)脱保护的聚乙二醇-聚苯乙烯(PEG-PS)接枝载体上，9-氟酰甲基氧羰基(Fmoc)固相合成十(l-丙烯基)-L-valinamide的优化。

Peptide research Pub Date : 1996-05-01

S A Kates, N A Solé, M Beyermann, G Barany, F Albericio

引用次数: 0