Basic life sciences最新文献_第5页

Myoglobin solvent structure at different temperatures. 不同温度下肌红蛋白的溶剂结构。

Basic life sciences Pub Date : 1996-01-01 DOI: 10.1007/978-1-4615-5847-7_28

B V Daniels, B P Schoenborn, Z R Korszun

引用次数: 5

The chemical reactivity and structure of collagen studied by neutron diffraction. 用中子衍射法研究了胶原蛋白的化学反应性和结构。

Basic life sciences Pub Date : 1996-01-01 DOI: 10.1007/978-1-4615-5847-7_32

T J Wess, L Wess, A Miller

{"title":"The chemical reactivity and structure of collagen studied by neutron diffraction.","authors":"T J Wess, L Wess, A Miller","doi":"10.1007/978-1-4615-5847-7_32","DOIUrl":"https://doi.org/10.1007/978-1-4615-5847-7_32","url":null,"abstract":"The chemical reactivity of collagen can be studied using neutron diffraction (a non-destructive technique), for certain reaction types. Collagen contains a number of lysine and hydroxylysine side chains that can react with aldehydes and ketones, or these side chains can themselves be converted to aldehydes by lysyl oxidase. The reactivity of these groups not only has an important role in the maintenance of mechanical strength in collagen fibrils, but can also manifest pathologically in the cases of aging, diabetes (reactivity with a variety of sugars) and alcoholism (reactivity with acetaldehyde). The reactivity of reducing groups with collagen can be studied by neutron diffraction, since the crosslink formed in the adduction process is initially of a Schiff base or keto-imine nature. The nature of this crosslink allows it to be deuterated, and the position of this relatively heavy scattering atom can be used in a process of phase determination by multiple isomorphous replacement. This process was used to study the following: the position of natural crosslinks in collagen; the position of adducts in tendon from diabetic rats in vivo and the in vitro position of acetaldehyde adducts in tendon.","PeriodicalId":8697,"journal":{"name":"Basic life sciences","volume":"64 ","pages":"369-83"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/978-1-4615-5847-7_32","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19988977","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: 1

Structural model of the 50S subunit of E. coli ribosomes from solution scattering. 溶液散射法研究大肠杆菌核糖体50S亚基结构模型。

Basic life sciences Pub Date : 1996-01-01 DOI: 10.1007/978-1-4615-5847-7_15

D I Svergun, M H Koch, J S Pedersen, I N Serdyuk

{"title":"Structural model of the 50S subunit of E. coli ribosomes from solution scattering.","authors":"D I Svergun, M H Koch, J S Pedersen, I N Serdyuk","doi":"10.1007/978-1-4615-5847-7_15","DOIUrl":"https://doi.org/10.1007/978-1-4615-5847-7_15","url":null,"abstract":"The application of new methods of small-angle scattering data interpretation to a contrast variation study of the 50S ribosomal subunit of Escherichia coli in solution is described. The X-ray data from contrast variation with sucrose are analyzed in terms of the basic scattering curves from the volume inaccessible to sucrose and from the regions inside this volume occupied mainly by RNA and by proteins. From these curves models of the shape of the 50S and its RNA-rich core are evaluated and positioned so that their difference produces a scattering curve which is in good agreement with the scattering from the protein moiety. Based on this preliminary model, the X-ray and neutron contrast variation data of the 50S subunit in aqueous solutions are interpreted in the frame of the advanced two-phase model described by the shapes of the 50S subunit and its RNA-rich core taking into account density fluctuations inside the RNA and the protein moiety. The shape of the envelope of the 50S subunit and of the RNA-rich core are evaluated with a resolution of about 40 A. The shape of the envelope is in good agreement with the models of the 50S subunit obtained from electron microscopy on isolated particles. The shape of the RNA-rich core correlates well with the model of the entire particle determined by the image reconstruction from ordered sheets indicating that the latter model which is based on the subjective contouring of density maps is heavily biased towards the RNA.","PeriodicalId":8697,"journal":{"name":"Basic life sciences","volume":"64 ","pages":"149-74"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19989066","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: 6

Neutron reflectivity studies of single lipid bilayers supported on planar substrates. 平面基底上单脂质双层的中子反射率研究。

Basic life sciences Pub Date : 1996-01-01 DOI: 10.1007/978-1-4615-5847-7_19

S Krueger, B W Koenig, W J Orts, N F Berk, C F Majkrzak, K Gawrisch

{"title":"Neutron reflectivity studies of single lipid bilayers supported on planar substrates.","authors":"S Krueger, B W Koenig, W J Orts, N F Berk, C F Majkrzak, K Gawrisch","doi":"10.1007/978-1-4615-5847-7_19","DOIUrl":"https://doi.org/10.1007/978-1-4615-5847-7_19","url":null,"abstract":"Neutron reflectivity was used to probe the structure of single phosphatidylcholine (PC) lipid bilayers adsorbed onto a planar silicon surface in an aqueous environment. Fluctuations in the neutron scattering length density profiles perpendicular to the silicon/water interface were determined for different lipids as a function of the hydrocarbon chain length. The lipids were studied in both the gel and liquid crystalline phases by monitoring changes in the specularly-reflected neutron intensity as a function of temperature. Contrast variation of the neutron scattering length density was applied to both the lipid and the solvent. Scattering length density profiles were determined using both model-independent and model-dependent fitting methods. During the reflectivity measurements, a novel experimental set-up was implemented to decrease the incoherent background scattering due to the solvent. Thus, the reflectivity was measured to Q approximately 0.3 A-1, covering up to seven orders of magnitude in reflected intensity, for PC bilayers in D2O and silicon-matched (38% D2O/62% H2O) water. The kinetics of lipid adsorption at the silicon/water interface were also explored by observing changes in the reflectivity at low Q values under silicon-matched water conditions.","PeriodicalId":8697,"journal":{"name":"Basic life sciences","volume":"64 ","pages":"205-13"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19989069","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: 6

Probing self assembly in biological mixed colloids by SANS, deuteration, and molecular manipulation. 用SANS、氘化和分子操作探测生物混合胶体中的自组装。

Basic life sciences Pub Date : 1996-01-01 DOI: 10.1007/978-1-4615-5847-7_16

R P Hjelm, P Thiyagarajan, A Hoffman, C Schteingart, H Alkan-Onyuksel

{"title":"Probing self assembly in biological mixed colloids by SANS, deuteration, and molecular manipulation.","authors":"R P Hjelm, P Thiyagarajan, A Hoffman, C Schteingart, H Alkan-Onyuksel","doi":"10.1007/978-1-4615-5847-7_16","DOIUrl":"https://doi.org/10.1007/978-1-4615-5847-7_16","url":null,"abstract":"Small-angle neutron scattering was used to obtain information on the form and molecular arrangement of particles in mixed colloids of bile salts with phosphatidylcholine, and bile salts with monoolein. Both types of systems showed the same general characteristics. The particle form was highly dependent on total lipid concentration. At the highest concentrations the particles were globular mixed micelles with an overall size of 50A. As the concentration was reduced the mixed micelles elongated, becoming rodlike with diameter about 50A. The rods had a radial core-shell structure in which the phosphatidylcholine or monoolein fatty tails were arranged radially to form the core with the headgroups pointing outward to form the shell. The bile salts were at the interface between the shell and core with the hydrophilic parts facing outward as part of the shell. The lengths of the rods increased and became more polydispersed with dilution. At sufficiently low concentrations the mixed micelles transformed into single bilayer vesicles. These results give insight on the physiological function of bile and on the rules governing the self assembly of bile particles in the hepatic duct and the small intestine.","PeriodicalId":8697,"journal":{"name":"Basic life sciences","volume":"64 ","pages":"175-90"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19989067","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: 3

Neutron scattering studies on chromatin higher-order structure. 染色质高阶结构的中子散射研究。

Basic life sciences Pub Date : 1996-01-01 DOI: 10.1007/978-1-4615-5847-7_13

V Graziano, S E Gerchman, D K Schneider, V Ramakrishnan

引用次数: 2

Protein-detergent interactions in single crystals of membrane proteins studied by neutron crystallography. 用中子晶体学研究膜蛋白单晶中的蛋白质-洗涤剂相互作用。

Basic life sciences Pub Date : 1996-01-01 DOI: 10.1007/978-1-4615-5847-7_23

P A Timmins, E Pebay-Peyroula

引用次数: 2

The structure of the muscle protein complex 4Ca2+.troponin C.troponin I. Monte Carlo modeling analysis of small-angle X-ray data. 肌肉蛋白复合物4Ca2+的结构。小角度x射线数据的蒙特卡罗建模分析。

Basic life sciences Pub Date : 1996-01-01

G A Olah, J Trewhella