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21.
Estimation of Enantiomeric Impurity in Piperidin‐3‐Amine by Chiral HPLC With Precolumn Derivatization
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Chittabathina Venkata Raghunadha Babu Nagi Reddy Vuyyuru K. Padmaja Reddy M.V. Suryanarayana K. Mukkanti 《Chirality》2014,26(12):775-779
A simple, precise, accurate, robust chiral high‐performance liquid chromatographic (chiral HPLC) method was developed for estimation of (S)‐piperidin‐3‐amine (S‐isomer) in (R)‐piperidin‐3‐amine dihydrochloride (R‐AMP). As AMP is a high‐melting solid and nonchromophoric compound, development of a suitable chiral method is a challenging task. The proposed chiral HPLC‐UV method involves a precolumn derivatization technique with para toluene sulphonyl chloride (PTSC) in the presence of a base to introduce chromophore into analytes. It utilizes chiralpak AD‐H column with a simple mobile phase of 0.1% diethyl amine in ethanol with a 0.5 mL/min flow rate. Analytes were monitored by using a UV detector at 228 nm. The resolution between the two enantiomers was more than 4.0. The developed method was validated as per current International Conference on Harmonization (ICH) guidelines. Chirality 26:775–779, 2014. © 2014 Wiley Periodicals, Inc. 相似文献
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23.
N Jayanthi Bia M Ramachandra Pai P Suryanarayana Murthy T A Venkitasubramanian 《Archives of biochemistry and biophysics》1975,168(1):230-234
Fructose diphosphate aldolase has been purified to homogeneity from Mycobacterium smegmatis. Physicochemical studies showed that the enzyme is a tetramer of molecular weight 158,000. Mycobacterium smegmatis aldolase, though a bacterial enzyme, possesses properties similar to other class I aldolases. Inactivation of the enzyme by sodium borohydride in presence of dihydroxyacetone phosphate suggested the formation of a Schiff-base intermediate. 相似文献
24.
Double stranded cDNA for the foot and mouth disease virus was prepared, restricted withBamH 1 or ligated to linkers withBamH 1 sticky ends and cloned inBamH 1 site in the expression vector, pU R222. The cDNA was also cloned at thePst 1 site in the same vector by the dC/dG tailing method. They were transferred intoE. coli to give colourless colonies in the presence of the dye, X-gal. Many of them showed positive signal on hybridization with32P-labelled viral RNA. The middleBamH1 fragment of the cDNA is known to carry the gene for the major antigen and some non-structural proteins. The clones carrying the recombinant DNA produced proteins which cross-reacted with the antibodies generated against the structural proteins of the virus in an enzyme linked immunosorbent assay, indicating that the cDNA of the major antigen is expressed in the cloned cell. 相似文献
25.
S Suryanarayana D A Daunt M Von Zastrow B K Kobilka 《The Journal of biological chemistry》1991,266(23):15488-15492
Previous studies have shown that differences in subtype-specific ligand binding between alpha 2 and beta 2 adrenergic receptors are largely determined by the seventh hydrophobic domain. Here, we report that a single amino acid substitution (Phe412----Asn) in the seventh hydrophobic domain of the alpha 2 adrenergic receptor reduces affinity for the alpha 2 antagonist yohimbine by 350-fold and increases affinity for beta antagonist alprenolol by 3000-fold. The affinity of this mutant receptor alpha 2F----N for several alpha and beta adrenergic receptor agonists and antagonists was determined. Beta adrenergic receptor antagonists containing an oxygen atom linking the amino side chain with the aromatic ring bound to alpha 2F----N with high affinity, while the beta receptor antagonist sotalol, which lacks this oxygen, bound with low affinity. These data suggest that the Asn residue is involved in conferring specificity for binding to a specific class of beta receptor antagonists. 相似文献
26.
Primary structure of belladonna mottle virus coat protein 总被引:1,自引:0,他引:1
S Suryanarayana N A Rao M R Murthy H S Savithri 《The Journal of biological chemistry》1989,264(11):6273-6279
The coat protein of belladonna mottle virus (a tymovirus) was cleaved by trypsin and chymotrypsin, and the peptides were separated by high performance liquid chromatography using a combination of gel permeation, reverse phase, and ion pair chromatography. The peptides were sequenced manually using the 4-N, N-dimethylaminoazobenzene-4'-isothiocyanate/phenyl isothiocyanate double-coupling method. The chymotryptic peptides were aligned by overlapping sequences of tryptic peptides and by homology with another tymovirus, eggplant mosaic virus. The belladonna mottle virus is more closely related to eggplant mosaic virus than to turnip yellow mosaic virus, the type member of this group, as evident from the sequence homologies of 57 and 32%, respectively. The accumulation of basic residues at the amino terminus implicated in RNA-protein interactions in many spherical plant viruses was absent in all the three sequences. Interestingly, the amino-terminal region is the least conserved among the tymoviruses. The longest stretch of conserved sequence between belladonna mottle virus and eggplant mosaic virus was residues 34-44, whereas it was residues 96-102 in the case of belladonna mottle virus and turnip yellow mosaic virus. A tetrapeptide in the region (residues 154-157) was found to be common for all the three sequences. It is possible that these conserved regions (residues 34-44, 96-102, 154-157) are involved in either intersubunit or RNA-protein interactions. 相似文献
27.
Jane L Wagstaff Jonathan N Pruneda Stefan MV Freund David Komander 《The EMBO journal》2017,36(24):3555-3572
The Ser/Thr protein kinase PINK1 phosphorylates the well‐folded, globular protein ubiquitin (Ub) at a relatively protected site, Ser65. We previously showed that Ser65 phosphorylation results in a conformational change in which Ub adopts a dynamic equilibrium between the known, common Ub conformation and a distinct, second conformation wherein the last β‐strand is retracted to extend the Ser65 loop and shorten the C‐terminal tail. We show using chemical exchange saturation transfer (CEST) nuclear magnetic resonance experiments that a similar, C‐terminally retracted (Ub‐CR) conformation also exists at low population in wild‐type Ub. Point mutations in the moving β5 and neighbouring β‐strands shift the Ub/Ub‐CR equilibrium. This enabled functional studies of the two states, and we show that while the Ub‐CR conformation is defective for conjugation, it demonstrates improved binding to PINK1 through its extended Ser65 loop, and is a superior PINK1 substrate. Together our data suggest that PINK1 utilises a lowly populated yet more suitable Ub‐CR conformation of Ub for efficient phosphorylation. Our findings could be relevant for many kinases that phosphorylate residues in folded protein domains. 相似文献
28.
Potukuchi Venkata Gurunadha Krishna Sarma Lokanathan Srikanth Katari Venkatesh P Suryanarayana Murthy Puranam Usha Sarma 《Bioinformation》2013,9(13):690-695
It has been observed that mycobacterial species has high content of cardiolipin (CL) in their cell membranes more so pathogenic
mycobacteria and in bacteria CL activates polymerases, gyrases by removing the bound ADP. Therefore, in the present study
cardiolipin synthase (cls) which catalyses the formation of CL was isolated purified and characterized from the cell membrane of
Mycobacterium phlei. The purified cls obtained from C-18 RP-HPLC column had a molecular weight of 58 kDa with an isoelectric
point of 4.5. The enzyme activity (11.5+0.15 µM of CL phosphorous. ml-1 minute-1 for PG as substrate and 14+0.35µM of CL
phosphorous. ml-1 minute-1 for CDP-DG as substrate) was optimal at pH 4.8 and showed KM values of 55+0.05µM and 2.56+0.04µM
for phosphatidyl glycerol and CDP-diacylglycerol, respectively, with an absolute requirement of Mg2+ and Mn2+ ions for its activity
however, Ca2+ ions inhibited the activity of the cls. The partial amino acid sequence of cls showed significant homology with pgsA3
gene of M. tuberculosis and in this organism the CL biosynthesis is very high having three genes coding for PLs biosynthesis
therefore, enzymes involved in CL biosynthesis may be an attractive drug target in the development of new antimycobacterial
drugs. 相似文献
29.
Neelima Arora Amit Kumar Banerjee Srilaxmi Mutyala Upadhyayula Suryanarayana Murty 《Bioinformation》2009,3(10):446-453
Xylanase is an industrially important enzyme having wide range of applications especially in paper industry. It is crucial to gain
an understanding about the structure and functional aspects of various xylanases produced from diverse sources. In this study, a
bioinformatics and molecular modeling approach was adopted to explore properties and structure of xylanases. Physico-chemical
properties were predicted and prediction of motifs, disulfide bridges and secondary structure was performed for functional
characterization. Apart from these analyses, three dimensional structures were constructed and stereo-chemical quality was
evaluated by different structure validation tools. Comparative catalytic site analysis and assessment was performed to extract
information about the important residues. Asn72 was found to be the common residue in the active sites of the proteins
and P35809. Q12603相似文献
30.