Journal of biophysics (Hindawi Publishing Corporation : Online)最新文献_第4页

EI of the Phosphotransferase System of Escherichia coli: Mathematical Modeling Approach to Analysis of Its Kinetic Properties. 大肠杆菌磷酸转移酶体系的EI:动力学性质分析的数学建模方法。

Journal of biophysics (Hindawi Publishing Corporation : Online) Pub Date : 2011-01-01 Epub Date: 2011-03-20 DOI: 10.1155/2011/579402

T A Karelina, H Ma, I Goryanin, O V Demin

引用次数: 15

F-ratio test and hypothesis weighting: a methodology to optimize feature vector size. f比检验和假设加权:一种优化特征向量大小的方法。

Journal of biophysics (Hindawi Publishing Corporation : Online) Pub Date : 2011-01-01 Epub Date: 2011-08-17 DOI: 10.1155/2011/290617

R M Dünki, M Dressel

引用次数: 1

CsmA Protein is Associated with BChl a in the Baseplate Subantenna of Chlorosomes of the Photosynthetic Green Filamentous Bacterium Oscillochloris trichoides belonging to the Family Oscillochloridaceae. 光合绿色丝状细菌trichoides Oscillochloris叶绿体基板亚天线中的CsmA蛋白与BChl a相关。

Journal of biophysics (Hindawi Publishing Corporation : Online) Pub Date : 2011-01-01 Epub Date: 2011-09-15 DOI: 10.1155/2011/860382

Anastasiya Zobova, Alexandra Taisova, Eugeny Lukashev, Nataliya Fedorova, Ludmila Baratova, Zoya Fetisova

{"title":"CsmA Protein is Associated with BChl a in the Baseplate Subantenna of Chlorosomes of the Photosynthetic Green Filamentous Bacterium Oscillochloris trichoides belonging to the Family Oscillochloridaceae.","authors":"Anastasiya Zobova, Alexandra Taisova, Eugeny Lukashev, Nataliya Fedorova, Ludmila Baratova, Zoya Fetisova","doi":"10.1155/2011/860382","DOIUrl":"https://doi.org/10.1155/2011/860382","url":null,"abstract":"The baseplate subantenna in chlorosomes of green anoxygenic photosynthetic bacteria, belonging to the families Chloroflexaceae and Chlorobiaceae, is known to represent a complex of bacteriochlorophyll (BChl) a with the ~6 kDa CsmA proteins. Earlier, we showed the existence of a similar BChl a subantenna in chlorosomes of the photosynthetic green bacterium Oscillochloris trichoides, member of Oscillochloridaceae, the third family of green photosynthetic bacteria. However, this BChl a subantenna was not visually identified in absorption spectra of isolated Osc. trichoides chlorosomes in contrast to those of Chloroflexaceae and Chlorobiaceae. In this work, using room and low-temperature absorbance and fluorescence spectroscopy and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of alkaline-treated and untreated chlorosomes of Osc. trichoides, we showed that the baseplate BChl a subantenna does exist in Oscillochloridaceae chlorosomes as a complex of BChl a with the 5.7 kDa CsmA protein. The present results support the idea that the baseplate subantenna, representing a complex of BChl a with a ~6 kDa CsmA protein, is a universal interface between the BChl c subantenna of chlorosomes and the nearest light-harvesting BChl a subantenna in all three known families of green anoxygenic photosynthetic bacteria.","PeriodicalId":73623,"journal":{"name":"Journal of biophysics (Hindawi Publishing Corporation : Online)","volume":"2011 ","pages":"860382"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2011/860382","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30016891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Exploring the membrane mechanism of the bioactive peptaibol ampullosporin a using lipid monolayers and supported biomimetic membranes. 利用脂质单层膜和支撑生物仿生膜探索生物活性哌替波尔安普霉素 a 的膜机理。

Journal of biophysics (Hindawi Publishing Corporation : Online) Pub Date : 2010-01-01 Epub Date: 2011-02-17 DOI: 10.1155/2010/179641

Marguerita Eid, Sonia Rippa, Sabine Castano, Bernard Desbat, Joël Chopineau, Claire Rossi, Laure Béven

{"title":"Exploring the membrane mechanism of the bioactive peptaibol ampullosporin a using lipid monolayers and supported biomimetic membranes.","authors":"Marguerita Eid, Sonia Rippa, Sabine Castano, Bernard Desbat, Joël Chopineau, Claire Rossi, Laure Béven","doi":"10.1155/2010/179641","DOIUrl":"10.1155/2010/179641","url":null,"abstract":"Ampullosporin A is an antimicrobial, neuroleptic peptaibol, the behavior of which was investigated in different membrane mimetic environments made of egg yolk L-α-phosphatidylcholine. In monolayers, the peptaibol adopted a mixed α/3(10)-helical structure with an in-plane orientation. The binding step was followed by the peptide insertion into the lipid monolayer core. The relevance of the inner lipid leaflet nature was studied by comparing ampullosporin binding on a hybrid bilayer, in which this leaflet was a rigid alkane layer, and on supported fluid lipid bilayers. The membrane binding was examined by surface plasmon resonance spectroscopy and the effect on lipid dynamics was explored using fluorescence recovery after photobleaching. In the absence of voltage and at low concentration, ampullosporin A substantially adsorbed onto lipid surfaces and its interaction with biomimetic models was strongly modified depending on the inner leaflet structure. At high concentration, ampullosporin A addition led to the lipid bilayers disruption.","PeriodicalId":73623,"journal":{"name":"Journal of biophysics (Hindawi Publishing Corporation : Online)","volume":"2010 ","pages":"179641"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3042626/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"29741049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Computational laser spectroscopy in a biological tissue. 生物组织中的计算激光光谱学。

Journal of biophysics (Hindawi Publishing Corporation : Online) Pub Date : 2010-01-01 Epub Date: 2010-04-07 DOI: 10.1155/2010/253763

M Gantri, H Trabelsi, E Sediki, R Ben Salah

{"title":"Computational laser spectroscopy in a biological tissue.","authors":"M Gantri, H Trabelsi, E Sediki, R Ben Salah","doi":"10.1155/2010/253763","DOIUrl":"https://doi.org/10.1155/2010/253763","url":null,"abstract":"We present a numerical spectroscopic study of visible and infrared laser radiation in a biological tissue. We derive a solution of a general two-dimensional time dependent radiative transfer equation in a tissue-like medium. The used model is suitable for many situations especially when the external source is time-dependent or continuous. We use a control volume-discrete ordinate method associated with an implicit three-level second-order time differencing scheme. We consider a very thin rectangular biological-tissue-like medium submitted to a visible or a near infrared light sources. The RTE is solved for a set of different wavelength source. All sources are assumed to be monochromatic and collimated. The energetic fluence rate is computed at a set of detector points on the boundaries. According to the source type, we investigate either the steady-state or transient response of the medium. The used model is validated in the case of a heterogeneous tissue-like medium using referencing experimental results from the literature. Also, the developed model is used to study changes on transmitted light in a rat-liver tissue-like medium. Optical properties depend on the source wavelength and they are taken from the literature. In particular, light-transmission in the medium is studied for continuous wave and for short pulse.","PeriodicalId":73623,"journal":{"name":"Journal of biophysics (Hindawi Publishing Corporation : Online)","volume":"2010 ","pages":"253763"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2010/253763","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28925695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Navigation by induction-based magnetoreception in elasmobranch fishes. 板鳃科鱼类感应式磁接受导航。

Journal of biophysics (Hindawi Publishing Corporation : Online) Pub Date : 2009-01-01 Epub Date: 2009-10-18 DOI: 10.1155/2009/380976

T C A Molteno, W L Kennedy

引用次数: 31

An overview of the importance of conformational flexibility in gene regulation by the transcription factors. 概述转录因子在基因调控中的构象灵活性的重要性。

Journal of biophysics (Hindawi Publishing Corporation : Online) Pub Date : 2009-01-01 Epub Date: 2010-02-04 DOI: 10.1155/2009/210485

Shagufta H Khan, Raj Kumar

{"title":"An overview of the importance of conformational flexibility in gene regulation by the transcription factors.","authors":"Shagufta H Khan, Raj Kumar","doi":"10.1155/2009/210485","DOIUrl":"https://doi.org/10.1155/2009/210485","url":null,"abstract":"A number of proteins with intrinsically disordered (ID) regions/domains are reported to be found disproportionately higher in transcription factors. Available evidences suggest that presence of ID region/domain within a transcription factor plays an important role in its biological functions. These ID sequences provide large flexible surfaces that can allow them to make more efficient physical and functional interactions with their target partners. Since transcription factors regulate expression of target genes by interacting with specific coregulatory proteins, these ID regions/domains can be used as a platform for such large macromolecular interactions, and may represent a mechanism for regulation of cellular processes. The precise structural basis for the function of these ID regions/domains of the transcription factors remains to be determined. In the recent years there has been growing evidence suggesting that an induced fit-like process leads to imposition of folded functional structure in these ID domains on which large multiprotein complexes are built. These multiprotein complexes may eventually dictate the final outcome of the gene regulation by the transcription factors.","PeriodicalId":73623,"journal":{"name":"Journal of biophysics (Hindawi Publishing Corporation : Online)","volume":"2009 ","pages":"210485"},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2009/210485","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28723406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Tropomyosin period 3 is essential for enhancement of isometric tension in thin filament-reconstituted bovine myocardium. 原肌球蛋白第3期对增强牛细丝重建心肌的等长张力至关重要。

Journal of biophysics (Hindawi Publishing Corporation : Online) Pub Date : 2009-01-01 Epub Date: 2009-10-13 DOI: 10.1155/2009/380967

Masataka Kawai, Xiaoying Lu, Sarah E Hitchcock-Degregori, Kristen J Stanton, Michael W Wandling

{"title":"Tropomyosin period 3 is essential for enhancement of isometric tension in thin filament-reconstituted bovine myocardium.","authors":"Masataka Kawai, Xiaoying Lu, Sarah E Hitchcock-Degregori, Kristen J Stanton, Michael W Wandling","doi":"10.1155/2009/380967","DOIUrl":"https://doi.org/10.1155/2009/380967","url":null,"abstract":"Tropomyosin (Tm) consists of 7 quasiequivalent repeats known as \"periods,\" and its specific function may be associated with these periods. To test the hypothesis that either period 2 or 3 promotes force generation by inducing a positive allosteric effect on actin, we reconstituted the thin filament with mutant Tm in which either period 2 (Delta2Tm) or period 3 (Delta3Tm) was deleted. We then studied: isometric tension, stiffness, 6 kinetic constants, and the pCa-tension relationship. N-terminal acetylation of Tm did not cause any differences. The isometric tension in Delta2Tm remained unchanged, and was reduced to approximately 60% in Delta3Tm. Although the kinetic constants underwent small changes, the occupancy of strongly attached cross-bridges was not much different. The Hill factor (cooperativity) did not differ significantly between Delta2Tm (1.79 +/- 0.19) and the control (1.73 +/- 0.21), or Delta3Tm (1.35 +/- 0.22) and the control. In contrast, pCa(50) decreased slightly in Delta2Tm (5.11 +/- 0.07), and increased significantly in Delta3Tm (5.57 +/- 0.09) compared to the control (5.28 +/- 0.04). These results demonstrate that, when ions are present at physiological concentrations in the muscle fiber system, period 3 (but not period 2) is essential for the positive allosteric effect that enhances the interaction between actin and myosin, and increases isometric force of each cross-bridge.","PeriodicalId":73623,"journal":{"name":"Journal of biophysics (Hindawi Publishing Corporation : Online)","volume":"2009 ","pages":"380967"},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2009/380967","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28694322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 18

DSC Study of Collagen in Disc Disease. 椎间盘病变中胶原蛋白的DSC研究。

Journal of biophysics (Hindawi Publishing Corporation : Online) Pub Date : 2009-01-01 Epub Date: 2010-02-09 DOI: 10.1155/2009/819635

S Skrzyński, A Sionkowska, A Marciniak

{"title":"DSC Study of Collagen in Disc Disease.","authors":"S Skrzyński, A Sionkowska, A Marciniak","doi":"10.1155/2009/819635","DOIUrl":"https://doi.org/10.1155/2009/819635","url":null,"abstract":"Differential scanning calorimetry (DSC) has been used to estimate the effect of disc disease on the collagen helix-coil transition and morphology for tissue extracted from patients during surgical operation. Forty discs were obtained from patients with degenerative disc disease undergoing surgery for low back pain. The patients were in the age between 20 and 70 years old. The specimens were kept wet during DSC experiment. The data allow the comparison between thermal stability of collagen tissue from healthy patients and from patients suffering from disc disease. In the paper the comparison between thermal helix-coil transition for collagen fibers from patients suffering from disc disease and collagen fibers from healthy organisms has been discussed. The heating rate has an influence on the position on denaturation temperatures of collagen in disc tissues. Higher helix-coil transition temperature of collagen in degenerated disc suggests that additional intermolecular cross linking of collagen fibers occurs. Denaturation temperatures of collagen in degenerated male disc possess smaller values than in female ones. Disc disease induces changes in collagen structure and leads to formation of additional crosslinks between collagen fibers.","PeriodicalId":73623,"journal":{"name":"Journal of biophysics (Hindawi Publishing Corporation : Online)","volume":"2009 ","pages":"819635"},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2009/819635","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28726048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Crystal Structural and Functional Analysis of the Putative Dipeptidase from Pyrococcus horikoshii OT3. 堀氏焦球菌二肽酶的晶体结构和功能分析。

Journal of biophysics (Hindawi Publishing Corporation : Online) Pub Date : 2009-01-01 Epub Date: 2009-06-28 DOI: 10.1155/2009/434038

Jeyaraman Jeyakanthan, Katsumi Takada, Masahide Sawano, Kyoko Ogasahara, Hisashi Mizutani, Naoki Kunishima, Shigeyuki Yokoyama, Katsuhide Yutani

{"title":"Crystal Structural and Functional Analysis of the Putative Dipeptidase from Pyrococcus horikoshii OT3.","authors":"Jeyaraman Jeyakanthan, Katsumi Takada, Masahide Sawano, Kyoko Ogasahara, Hisashi Mizutani, Naoki Kunishima, Shigeyuki Yokoyama, Katsuhide Yutani","doi":"10.1155/2009/434038","DOIUrl":"https://doi.org/10.1155/2009/434038","url":null,"abstract":"The crystal structure of a putative dipeptidase (Phdpd) from Pyrococcus horikoshii OT3 was solved using X-ray data at 2.4 A resolution. The protein is folded into two distinct entities. The N-terminal domain consists of the general topology of the alpha/beta fold, and the C-terminal domain consists of five long mixed strands, four helices, and two 3(10) helices. The structure of Phdpd is quite similar to reported structures of prolidases from P. furiosus (Zn-Pfprol) and P. horikoshii (Zn-Phdpd), where Zn ions are observed in the active site resulting in an inactive form. However, Phdpd did not contain metals in the crystal structure and showed prolidase activity in the absence of additional Co ions, whereas the specific activities increased by 5 times in the presence of a sufficient concentration (1.2 mM) of Co ions. The substrate specificities (X-Pro) of Phdpd were broad compared with those of Zn-Phdpd in the presence of Co ions, whose relative activities are 10% or less for substrates other than Met-Pro, which is the most favorable substrate. The binding constants of Zn-Phdpd with three metals (Zn, Co, and Mn) were higher than those of Phdpd and that with Zn was higher by greater than 2 orders, which were determined by DSC experiments. From the structural comparison of both forms and the above experimental results, it could be elucidated why the protein with Zn(2+) ions is inactive.","PeriodicalId":73623,"journal":{"name":"Journal of biophysics (Hindawi Publishing Corporation : Online)","volume":"2009 ","pages":"434038"},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2009/434038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28692659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20