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::The positions of the several sea urchin histone genes on the eukaryotic fragments of the chimeric plasmids pSp2 and pSp17 have been mapped relative to the Eco RI and Hind III restriction endonuclease sites on the plasmids. Two principal mapping methods using the electron microscope have been used: (a) the R-loop proce...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00626a040
更新日期:1977-04-05 00:00:00
abstract::An equimolar mixture of DL-[alpha-2H]- and DL-[alpha-13C]mandelate, when incubated with mandelate racemase (EC 5.1.2.2), shows conversion of singly labeled mandelate to unlabeled mandelate, due to solvent exchange of the alpha proton, while the level of doubly labeled mandelate remains at a constant low level. Similar...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00625a015
更新日期:1977-03-22 00:00:00
abstract::The solvent polarity dependence of the interaction between thiamin and tryptophan was studied by spectrophotometric methods. The ultraviolet (UV) data clearly indicate that the interaction is weakened when the complex is transferred from water to aqueous ethanol or aqueous dioxane. The interaction of thiamin and trypt...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00625a012
更新日期:1977-03-22 00:00:00
abstract::The mechanism of bovine intestinal 5'-nucleotide phosphodiesterase was investigated by determining kinetic constants of systematically varied substrates, with emphasis on esters of phosphonic acids (which have much higer Vmax values than conventional phosphodiester substrates), and by pre-steady-state kinetics using b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00625a011
更新日期:1977-03-22 00:00:00
abstract::The complete amino acid sequence of the major component myoglobin from the dwarf sperm whale, Kogia simus, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequenator. Three easily separable peptides were obtained by cleaving the protein at its two...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00624a010
更新日期:1977-03-08 00:00:00
abstract::An organic solvent soluble polypeptide has been isolated from photoreceptor complexes and chromatophores of Rhodospirillum rubrum. After extraction of the protein from lyophilized samples with 1:1 chloroform-methanol, it was purified by column chromatography. Its isoelectric point determined by isoelectric focusing wa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00624a011
更新日期:1977-03-08 00:00:00
abstract::DNA-dependent synthesis of beta-galactosidase was optimized in extracts made from cells lysed by a standard French pressure cell. Extracts made at 3200 psi synthesized up to 25-fold more beta-galactosidase than extracts made at 7500 psi. beta-Galactosidase synthesis was cyclic 3', 5' AMP dependent, as expected, and in...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00624a016
更新日期:1977-03-08 00:00:00
abstract::Isotope effects have been measured with Mg2+ as the activator and L-malate labeled with deuterium or tritium at carbon 2 as the substrate over the pH range 4-10. Comparison of the nearly pH-independent deuterium-isotope effect on V/Kmalate of 1.5 with the tritium effect of 2.0 by the method of Northrop (Northrop, D.B....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00623a002
更新日期:1977-02-22 00:00:00
abstract::The complete primary structure of the major component myoglobin from the Arctic minke whale, Balaenoptera acutorostrata, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequencer. Over 80% of the amino acid sequence was established from the three ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00623a023
更新日期:1977-02-22 00:00:00
abstract::The interactions of Pr(III) and Eu(III) with specifically nitrated derivatives of the basic bovine pancreatic trypsin inhibitor have been studied using optical spectroscopy and nuclear magnetic resonance (NMR) at 250 and 270 MHz. Stability constants for proton and metal binding to nitrotyrosines 10 and 21 determined o...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00623a015
更新日期:1977-02-22 00:00:00
abstract::Following ribonuclease digestion of methyl-3H-labeled B77 avian sarcoma virus RNA subunits, methylated oligonucleotides were isolated by diethylaminoethylcellulose chromotogrpahy. Partial nucleotide sequences were deduced from the known enzymatic specificities of the ribonucleases. In addition to methylated nucleoside...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00622a021
更新日期:1977-02-08 00:00:00
abstract::The binding of ethidium bromide, as monitored by fluorescence enhancement, to chromatin prepared by nuclease digestion has been compared with the binding of the dye to sheared chromatin. The nuclease preparation (native chromatin) is characterized by a high affinity region of the Scatchard plot (r = 0-0.025, K1 = 1 X ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00622a002
更新日期:1977-02-08 00:00:00
abstract::The high resolution proton nuclear magnetic resonance (NMR) spectra of the synthetic DNA block polymer d(C15A15)-d(T15G15) were studied in order to more completely understand telestability in DNA, and to provide fundamental NMR data on DNA helices and random coils. Spectra were measured in the spectral region from 0 t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00622a031
更新日期:1977-02-08 00:00:00
abstract::Malic enzyme from pigeon liver is alkylated by the substrate analogue bromopyruvate, resulting in the concomitant loss of its oxidative decarboxylase and oxalacetate decarboxylase activities, but not its ability to reduce alpha-keto acids. The inactivation of oxidative decarboxylase activity follows saturation kinetic...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00621a024
更新日期:1977-01-25 00:00:00
abstract::The gamma-phosphoryl groups of two intermediates (M-ATP and M-ADP-P1) in the pathway of MgATP hydrolysis by myosin undergo extensive oxygen exchange with water. Actin activates the overall rate of hydrolysis at a rate-limiting step which follows these exchange reactions. Thus, actin, by decreasing the turnover time of...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00620a022
更新日期:1977-01-11 00:00:00
abstract::Thermal pertubation difference spectra of sperm whale myoglobin (Mb) and soybean leghemoglobin a (Lb a) in the near-ultraviolet reveal similarities in the tryptophan environment of the two proteins. Of the two tryptophans in each protein, one has its indolyl NH group fully exposed to aqueous solvent, while the other b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00620a009
更新日期:1977-01-11 00:00:00
abstract::The association-dissociation kinetics of ribosomes from Escherichia coli have been studied under various conditions in a light-scattering stopped-flow apparatus. The dissociation reaction at 2 mg/ml at 25 degrees C, induced by lowering the MgCl2 concentration from 18 to 3 mM, can best be described by three independent...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00671a010
更新日期:1976-12-28 00:00:00
abstract::The luminescence properties (fluorescence and phosphorescence) of luliberin have been investigated at liquid-nitrogen temperature (77 K) in 50% ethylene glycolaqueous buffer at various pH's. Calculation of the energy-transfer efficiency between Trp and Tyr residues leads to an evaluation of the distance separating the...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00671a009
更新日期:1976-12-28 00:00:00
abstract::The fate of plasma and nuclear membrane polypeptides in preparations of acidic chromosomal protein from chicken erythrocytes has been investigated. It is shown that detergent extraction procedures (Nonidet P-40, Triton X-100, and saponin), commonly employed in the preparation of acidic chromosomal protein, cannot be r...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00670a034
更新日期:1976-12-14 00:00:00
abstract::In this report we provide biochemical evidence that a highly purified synaptic plasma membrane fraction derived from rat brain, after intraventricular injection of 35S-labeled sodium sulfate, is enriched in a number of large sulfated glycoproteins compared with a purified myelin fraction studied concurrently. A fracti...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00670a005
更新日期:1976-12-14 00:00:00
abstract::We have examined slow changes in the rate of ATP hydrolysis for purified dog kidney Na+ and K+ stimulated adenosine triphosphatase [(Na-K)ATPase] at various concentrations of free Mg2+, Mg-ATP, K+, and Na+. The effect of these ligands on the rate of ATP hydrolysis is explained by a rapid binding step determining the i...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00669a013
更新日期:1976-11-30 00:00:00
abstract::The kinetic and equilibrium CO binding properties of hemoglobin (Hb) M Iwate (alpha2 87 His leads to Tyr beta2) have been investigated. The results show that the alpha(Met) beta2 (CO) tetramer of this protein has a low affinity for CO, as indicated by the stopped-flow and flash-photolysis kinetic, as well as the CO bi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00669a022
更新日期:1976-11-30 00:00:00
abstract::The motion of the ethanolamine head group in unsonicated lipid bilayers above and below the phase transition is studied by means of deuterium and phosphorus magnetic resonance. For this purpose, dipalmitoyl-3-sn-phosphatidylethanolamine is selectively deuterated at the two ethanolamine carbon atoms. The deuterium quad...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00669a001
更新日期:1976-11-30 00:00:00
abstract::An empirical preduction algorithm which uses information on the shrs on either side) interactions in 20 proteins to assign every residue in a protein to one of five conformational states is described. The conformational states are defined in terms of the backbone dihedral angles of the residue so that the prediction a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00668a030
更新日期:1976-11-16 00:00:00
abstract::Galactosyltransferase (UDPgalactose:glycoprotein galactosyltransferase EC 2.4.1.22) was isolated from swine mesentary lymhromatography on Sepharose 4B colums containing covalently bound p-aminophenyl-beta-D-N-acetylglucosamine. The homogenous enzyme showed a single band on disc gel electrophoresis and had a specific a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00668a009
更新日期:1976-11-16 00:00:00
abstract::The phosphorylation of (Na+, K+)ATPase from the electric organ of the electric eel is dependent on Mg2+. The amount of phosphoenzyme formed was increased by K+ and decreased by Na+. Kinetic analyses indicate that a ternary complex of ATPase, Pi and Mg2+ is formed prior to phosphorylation of the protein. Calorimetric s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00668a002
更新日期:1976-11-16 00:00:00
abstract::The synthesis of 5-(2-oxalylethyl)-NADH, a reduced nicotinamide adenine dinucleotide (NADH) derivate with pyruvate covalently attached to the 5 position of the dihydronicotinamide ring over an additional methylene group has been described previously (Trommer, W.E., Blume, H., and Kapmeyer, H. (1976) Justus Liebigs Ann...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00668a012
更新日期:1976-11-16 00:00:00
abstract::Protein C is a vitamin K dependent protein present in bovine plasma (Stenflo, J. (1976), J. Biol. Chem. 251, 355). It is a glycoprotein (mol wt approximately 62 000) composed of a heavy chain (mol wt 41 000) and a light chain (mol wt 21 000). The heavy chain has an amino-terminal sequence of Asp-Thr-Asn-Gln and contai...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00667a022
更新日期:1976-11-02 00:00:00
abstract::Two intermediates in the biosynthetic pathway to bacterial menaquinones are o-succinylbenzoic acid and 1,4-dihydroxy-2-naphthoic acid. Cell-free extracts have been prepared from Escherichia coli which catalyze the conversion of labeled o-succinylbenzoic acid to the naphthoic acid and also to menaquinones. The naphthoa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00667a007
更新日期:1976-11-02 00:00:00
abstract::Histone redistributions between endogenous DNA in calf thymus chromatin and exogenous DNA from Clostridium perfringens (69% A + T) or from Micrococcus luteus (30% A + T) induced by 0.6 M NaCl or by 2% formaldehyde were studied by thermal denaturation. The observed redistribution occurred on histone Hl when the exogeno...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00666a002
更新日期:1976-10-19 00:00:00
abstract::A new procedure for the synthesis of the pyrophosphate bond has been employed in the preparation of nucleoside dipyrophosphates from nucleoside 3',5'-diphosphates. The method makes use of a powerful phosphorylating agent generated in a mixture of cyanoethyl phosphate, dicyclohexylcarbodiimide, and mesitylenesulfonyl c...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00666a012
更新日期:1976-10-19 00:00:00
abstract::The carbon-13 (13C) nuclear magnetic resonance (NMR) behavior of the hyperactive analogue of luteinizing-hormone-releasing hormone (LH-RH), des-Gly-NH2(10)-[D-Leu6]LH-RH ethylamide, has been studied. The spectra are compared with those of the hypoactive des-Gly-NH2(10)-[L-Leu6]LH-RH ethylamide. Spin-lattice relaxation...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00666a020
更新日期:1976-10-19 00:00:00
abstract::Sedimentation equilibrium results, obtained with bovine zinc-free insulin (with and without a component of proinsulin) at pH 7.0, I o.2, 25 degrees C, and up to a total concentration of 0.8 g/l., are shown to be consistent with three different polymerization patterns, all involving an isodesmic indefinite self-associa...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00666a018
更新日期:1976-10-19 00:00:00
abstract::A mass transport theory of the gel chromatographic procedure of Hummel and Dreyer for measuring the binding of small ligand molecules to macromolecules has been formulated for ligand-mediated macromolecular association. It is concluded that the Hummel-Dreyer procedure is the method of choice for quantitating ligand bi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00666a011
更新日期:1976-10-19 00:00:00
abstract::1-Deoxy-D-fructose was synthesized in 27% yield from D-glucosamine in a three-step procedure involving Raney nickel desulfurization and oxidative deamination with 3,5-di-tert-butyl- 1,2-benzoquinone applied to appropriate intermediates. 1-Deoxyfructose and its reduction products, 1-deoxyglucitol and 1-deoxymannitol, w...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00665a027
更新日期:1976-10-05 00:00:00
abstract::The inhibition of phosphorylase kinase catalytic activity by 0.1 M neutral salts was predicted by the Hofmeister series of anions. The site of action of the salts was determined by the following evidence to be on the phosphorylase kinase molecule directly, rather than on its protein substrate. (1) Nonactivated kinase ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00665a022
更新日期:1976-10-05 00:00:00
abstract::Rabbit muscle lactate dehydrogenase (LDH) was coupled to Sepharose in such a way that each molecule is expected to be attached via only one subunit. Dissociation of the bound active enzyme by several methods all yielded immobilized subunit derivatives which were inactive. These derivatives were capable of regenerating...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00664a013
更新日期:1976-09-21 00:00:00
abstract::The interaction of glutamyl-tRNA synthetase with tRNAGlu2 has been studied. The enzyme was purified to apparent homogeneity, and consists of a single chain with a molecular weight of 59 000. The sedimentation coefficient (sdegrees20,w) was found to be 3.7 S and suggests this enzyme is quite asymmetric. The enzyme bind...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00664a032
更新日期:1976-09-21 00:00:00
abstract::We find that specific oxidation for the Met-192 residue in delta-chymotrypsin to methionine sulfoxide results in a twofold increase in Km(app) and unchanged kcat in the hydrolysis of N-acetyl mono(amino acid) amide substrates. However, the catalyzed hydrolyses of N-acetyl dipeptide amide substrates by (methionine sulf...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00664a006
更新日期:1976-09-21 00:00:00
abstract::Steroid-receptor complexes formed at low temperature and ionic strength are unable to bind to target cell nuclei. After a temporary exposure to high ionic strength and/or temperature they become activated (i.e., able to bind to nuclei). However, there exists an equilibrium between activated and nonactivated complexes;...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00664a025
更新日期:1976-09-21 00:00:00