解剖学和形态学
麻醉学
听力与言语-语言病理学
行为科学
心脏和心血管系统
细胞和组织工程学
临床神经病学
危重症监护医学
牙科,口腔外科和医学
皮肤病学
急诊医学
内分泌学和新陈代谢
肠胃学和肝脏学
老人病学和老年医学
卫生保健科学和服务
血液学
免疫学
传染病
综合和补充性医学
医学伦理学
医学信息学
医学实验室技术
医学,全科和内科
医学,法律
医学,研究和试验
神经系统科学
护理
营养学和饮食学
产科医学和妇科医学
肿瘤学
眼科学
整形外科学
耳鼻喉科学
病理学
儿科学
周围血管疾病
药理学和药剂学
生理学
基本医疗保健
精神病学
公共、环境和职业卫生
放射学,核医学和医学成像
康复学
生殖生物学
呼吸系统
风湿病学
运动科学
外科学
毒理学
热带医学
泌尿学和肾脏学
病毒学
老年医学
健康政策和服务
心理学,临床
abstract::We analyzed the CD and uv absorption spectra of 5S RNA from Escherichia coli using the method developed in the preceding paper. The analysis of spectra of 5S RNA at 20 degrees C in 0.1M NaClO4, 2.5 mM Na+ (phosphate), pH 7.0, and 0.5 mM MgSO4 gave 7 +/- 3.6 A.U base pairs, 25 +/- 3.6 G.C base pairs, and 7.5 +/- 3.6 G....
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360310404
更新日期:1991-03-01 00:00:00
abstract::The Electrostatically Driven Monte Carlo (EDMC) method was applied in a study of a decamer of glycine whose conformational behavior is described by the Empirical Conformational Energy Program for Peptides (ECEPP/2) potential energy model. When free neutral end groups were used, it was found that conformations that wer...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360310306
更新日期:1991-02-15 00:00:00
abstract::We have found that tri-L-alanine (Ala3) can crystallize in a parallel-chain beta structure in addition to the previously known antiparallel-chain beta structure. Although the chain conformations in each structure are essentially similar, the ir and Raman spectra are distinctively different. We have calculated the norm...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360310208
更新日期:1991-02-05 00:00:00
abstract::The gel electrophoresis of spherical particles with a radius above 0.2 micron has not been reported yet. In the present study, video phase-contrast light microscopy is used to observe the motion of individual latex spheres, 0.52 micron in radius, during electrophoresis in 0.1% agarose gels. At 2 V/cm, the spheres init...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360291416
更新日期:1990-12-01 00:00:00
abstract::Depsipeptide analogues of peptide sequences can help in elucidating the role of specific hydrogen bonds in determining the conformation in peptides. The repeating pentapeptide and hexapeptide sequences of elastin have been suggested to contain a type II beta-turn with a 4----1 hydrogen bond. Depsipeptide analogues of ...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360291212
更新日期:1990-10-01 00:00:00
abstract::The linear viscoelastic and rheological properties of high molecular weight ovine submaxillary mucin (OSM) solution have been investigated in terms of the Newtonian steady-flow viscosity [eta(gamma)], the complex oscillatory viscosity [eta*(omega)], and the storage and loss shear moduli [G'(omega) and G"(omega)]. It w...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360291004
更新日期:1990-08-15 00:00:00
abstract::Individual ethidium-stained DNA molecules, embedded in an agarose gel made with electrophoresis buffer (0.05 molar salt), are observed using a fluorescence microscope. In the first experiment, open circular 66 kilobase pair (kbp) plasmids, immobilized by agarose fibers threaded through their centers, display entropic ...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360290807
更新日期:1990-07-01 00:00:00
abstract::The indirect solvent-induced effect on the free energy of binding of biopolymers is examined within the framework of classical statistical mechanics. We focus specifically on the role of the solute-solvent hydrogen bonding. In particular, we have estimated the first order solvent effect on the indirect interaction bet...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360290604
更新日期:1990-05-01 00:00:00
abstract::The pulsed-field gel electrophoresis (PFG) is a newly developing technique used in the fractionation of large DNA fragments. Advances in PFG demand a better understanding in the corresponding mechanisms of DNA dynamics in the gel network. Detailed experiments are needed to verify and to extend existing theoretical pre...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360290408
更新日期:1990-03-01 00:00:00
abstract::The 13C off-resonance rotating frame spin-lattice relaxation technique is applicable to the study of protein rotational diffusion behavior in a variety of experimental situations. The original formalism of James and co-workers (1978) (J. Amer. Chem. Soc. 100, 3590-3594) was constrained by the assumption of random isot...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360290302
更新日期:1990-02-15 00:00:00
abstract::Synthetic RNA poly[r(A-T)] has been synthesized and its CD spectral properties compared to those of poly[r(A-U)], poly[d(A-T)], and poly[d(A-U)] in various salt and ethanolic solutions. The CD spectra of poly[r(A-T)] in an aqueous buffer and of poly[d(A-T)] in 70.8% v/v ethanol are very similar, suggesting that they b...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360290210
更新日期:1990-02-05 00:00:00
abstract::Dielectric relaxation peak due to bound water was found around 100 MHz in poly(dG-dC).poly(dG-dC) and calf thymus DNA in water-ethanol mixtures with NaCl buffer. Relaxation time and strength show a transition for poly(dG-dC).poly(dG-dC) at an ethanol composition Cw = 0.45 (w/w) where the structural transition from B- ...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360300702
更新日期:1990-01-01 00:00:00
abstract::Aqueous solutions of DNA fragments with a contour length (500 A) near the persistence length at DNA concentrations ranging from 10 to 290 mg/mL solvent and a constant supporting electrolyte concentration of 0.01 M (predominantly NaCl) were examined by 23Na-nmr spectroscopy at temperatures of 20, 40, and 60 degrees C. ...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360300715
更新日期:1990-01-01 00:00:00
abstract::Infrared spectra of the amino acid residues in H2O solution have been obtained in the 1800-1400-cm-1 region. It has been established that amino acid residues of arginine, asparagine, glutamine, aspartic and glutamic acids, lysine, tyrosine, histidine, and phenylalanine have intensive absorption in this spectral region...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360301309
更新日期:1990-01-01 00:00:00
abstract::Raman spectra of series of aqueous solutions of peptides containing two amino acids, glycine-X, alanine-X, and serine-X, where X is an uncharged amino acid, show that the amide III band shifts systematically to lower frequencies as the side chain of the X amino acid becomes larger. The range of this shift is about 20 ...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360300511
更新日期:1990-01-01 00:00:00
abstract::Infrared spectra of poly(D,L-alanine), poly(L-glutamic acid), poly(L-lysine), silk fibroin, and tropomyosin have been registered for various conformations of the polypeptide chain. Assuming additivity of the main- and side-chain absorption, spectral parameters of amide I and II absorption bands corresponding to alpha-...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360301310
更新日期:1990-01-01 00:00:00
abstract::The conformation of a 13-residue C-peptide analogue of ribonuclease A, suc-AET-AAAKFLRAHA-CONH2, in NaDodSO4 solutions with respect to temperature was studied with CD. The equilibrium constant of unfolding yielded a straight line in a van't Hoff plot. In 10 mM NaDodSO4, delta G mu = 120 cal/mol, delta H mu = 700 cal/m...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360300315
更新日期:1990-01-01 00:00:00
abstract::The crystal and molecular structure of the pentapeptide Boc-D-Ala-delta Phe-Gly-delta Phe-D-Ala-OMe, containing two dehydrophenylalanine residues, was determined by x-ray diffraction. The molecule crystallizes in the orthorombic P2(1)2(1)2(1) space group, with a = 10.439(3), b = 15.319(3) and c = 21.099(4) A. In the s...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360300906
更新日期:1990-01-01 00:00:00
abstract::Solid state nmr methods were applied to the study of the motions and structural heterogeneity in polyglycine, sodium poly(L-glutamate), and poly(L-alanine). The response of both the main-chain and side-chain resonances to the addition of water was studied using static and magic-angle sample-spinning line shapes as wel...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360300705
更新日期:1990-01-01 00:00:00
abstract::The enzymatic activities of native myosin light chain kinases are subject to modification by interaction with Ca2(+)-calmodulin (CaM). The interaction between myosin light chain kinase isolated from turkey gizzard (tgMLCK) and calmodulin isolated from bovine testes (CaMbt) and wheat germ (CaMwg) has been examined by m...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360301113
更新日期:1990-01-01 00:00:00
abstract::Previous studies have demonstrated that His 12 plays a major role in the pH-dependent stability of the helix formed by the isolated C-peptide (residues 1-13 of ribonuclease A). Here, amino acid replacement experiments show that His 12+ stabilizes the C-peptide helix chiefly by interacting with Phe 8. The Phe 8 ... His...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360290104
更新日期:1990-01-01 00:00:00
abstract::Cyclic pentapeptides are excellent models for reverse turns and have been used extensively in our laboratory to explore the influence of different amino acid sequences on turn preference. This paper is divided into two parts: In the first, we review our previous studies of cyclic pentapeptides. We summarize work that ...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360290130
更新日期:1990-01-01 00:00:00
abstract::We describe a method to determine the magnitude of protein-induced DNA bends relative to a set of standard A tract bends using comparative gel electrophoresis. The DNA bend of interest was that induced by the catabolite activator protein (CAP), the transcriptional activator protein of the lac operon. The set of compar...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360290106
更新日期:1990-01-01 00:00:00
abstract::In Monte Carlo simulations of polymeric chains, the chains are most often represented as spheres, or cylinders with flat ends. In this methodological paper, we adopt a representation of the chains as spherocylinders (continuous cylinders ending in semispheres). With such a representation the testing for chain overlap,...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360281203
更新日期:1989-12-01 00:00:00
abstract::The secondary structure of a 38 kDa core protein from pig skin proteodermatan sulfate (PDS), was investigated in solution using CD and Fourier transform (FT) ir spectroscopy. Both techniques generally have provided complementary data on the secondary structures of proteins. CD spectral analysis has shown that the core...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360281109
更新日期:1989-11-01 00:00:00
abstract::A detailed description of the two observed solution conformations of the pentapeptide lactone fragment of actinomycin D is presented using the distance constraints obtained from two-dimensional nuclear Overhauser enhancement spectra in combination with minimum energy calculations. Low energy conformational states that...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360281010
更新日期:1989-10-01 00:00:00
abstract::CD experiments are reported for several coiled-coil species in the tyrosine/disulfide (approximately 250-350-nm) region. Intact noncross-linked tropomyosin (approximately 3 degrees C) shows a negative nonsymmetric band maximal at 280 nm. This spectrum is the sum over six tyrosines/chain, and has conformational signifi...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360280909
更新日期:1989-09-01 00:00:00
abstract::We have previously described [K. M. Sullivan and D. M. J. Lilley (1986) Cell 47, 817-827] a set of sequences, called C-type inducing sequences, which cause cruciform extrusion by adjacent inverted repeats to occur by an abnormal kinetic pathway involving a large denatured region of DNA. In this paper we apply statisti...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360280810
更新日期:1989-08-01 00:00:00
abstract::The synthetic peptide Gly-L-Ala-L-Phe (C14H19N3O4.2H2O; GAF) crystallizes in the monoclinic space group P2I1), with a = 5.879(1), b = 7.966(1), c = 17.754(2) A, beta = 95.14(2) degrees, Dx = 1.321 g cm-3, and Z = 2. The crystal structure was solved by direct methods using the program SHELXS-86 and refined to an R valu...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360280707
更新日期:1989-07-01 00:00:00
abstract::Spin-spin and spin-lattice 1H-nmr relaxation times of the sea anemone polypeptide anthopleurin-A were measured at frequencies of 200, 300, 400, and 500 MHz. Relaxation times were fitted iteratively by least squares regression to the isotropic tumbling model, Woessner's model for anisotropic motion, and Lipari and Szab...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360280303
更新日期:1989-03-01 00:00:00
abstract::The thermal conformational transitions of two sonicated samples of schizophyllan were studied in water-dimethylsulfoxide (DMSO) mixtures by high-sensitivity differential scanning calorimetry (DSC). Two transitions were observed over most of the range of solvent compositions. These were assigned to an internal change o...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360280208
更新日期:1989-02-01 00:00:00
abstract::Neurokinins and their receptors are a complex system consisting of at least three endogenous agents--substance P (SP), neurokinin A (NKA), and neurokinin B (NKB)--and their corresponding receptor types, respectively, NK-1, NK-2, and NK-3. Investigations on receptors have been made using sensitive and fairly selective ...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360280111
更新日期:1989-01-01 00:00:00
abstract::The protected tripeptide tert-butyloxycarbonyl-L-leucyl-L-aminosuccinyl-L-phenylalaninamide crystallizes in the orthorhombic space group P2(1)2(1)2(1), with a = 6.214(3), b = 12.832(3), c = 33.094(4) A, Z = 4. The structure was solved by direct methods using MULTAN 80 and refined to an R value of 0.055 for 1458 reflec...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360280116
更新日期:1989-01-01 00:00:00
abstract::Molecular dynamics simulation, with backbone constraints for 20 ps of equilibration and simulation, of a repeating polypeptide segment, Gln-Pro-His-Gln-Pro-Leu-Gln-Pro-His-Gln-Pro-Leu-Gln-Pro-Met-(Gln-Pro-Leu )4, constituting residues 112-138 of bovine amelolgenin, a 19.35 kD hydrophobic protein, are discussed. It is ...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360280130
更新日期:1989-01-01 00:00:00
abstract::The synthetic peptide of sequence H-Ala-Ser-Thr-Thr-Thr-Asn-Tyr-Thr-OH, termed peptide T, a competitor of the Human Immunodeficiency Virus in the binding to human T cells, and its C-terminal pentapeptide fragment, were studied by 1H-nmr in DMSO solution to determine conformational preferences. The observation of nucle...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.360280142
更新日期:1989-01-01 00:00:00
abstract::Circular dichroic spectra and oscillator strengths of the π-π transition near 190 nm are calculated for helical (Gly)6 and (Ala)6 at 30° intervals of the backbone torsion angles (ϕ,ψ) over the range -180° ≤ ϕ ≤ -60°, -60° ≤ ψ ≤ 180°, using the partially dispersive normal mode treatment of the dipole interaction model....
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.1981.360200210
更新日期:1981-02-01 00:00:00
abstract::The IR data for the R1 CO-O-CHR2 -CO-NHR3 derivatives are interpreted in terms of a H…π interaction involving the NH bond and the π orbitals of the ester function and giving rise to a high ν(CO) frequency and a low ν frequency. The resulting molecular conformation corresponds to the angular values ϕ # -90°, ψ # 0°. ...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.1981.360200112
更新日期:1981-01-01 00:00:00
abstract::A conformational study of poly-L-serine has shown that it can exist in the left-handed α-helical form. A study of a pair of peptide units with the serine sidegroup attached to the α carbon atom linking the two units showed that OH ⃛O hydrogen bonds between the OH group of the side chain and a carbonyl oxygen of the f...
journal_title:Biopolymers
pub_type: 杂志文章
doi:10.1002/bip.1968.360060403
更新日期:1968-04-01 00:00:00