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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Glycoconjugate journal 13 (1996), S. 401-413 
    ISSN: 1573-4986
    Keywords: oligosialoglycosphingolipid ; sulfated sialic acid ; sea urchin sperm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Novel sulfated and nonsulfated oligosialyglycosphingolipids were isolated from sperm of the sea urchin,Hemicentrotus pulcherrimus, and their structures were established as follows: ±HSO3→Neu5Acα2→(8Neu5Acα2→)n→6G1cβ1→1´Cer, wheren=0, 1, 2, 3. This provides the first evidence for the natural occurrence of a tetrasialic acid structure in glycosphingolipids. The finding of sulfated oligosialyl chains is especially noteworthy in that the sulfate group exclusively resides on the C-8 of the nonreducing terminal residues of oligo/polysialyl chains and that sulfation appears to be a termination signal for elongation of oligosialyl chains. Sulfation at the nonreducing terminal Neu5Ac residues of oligosialyl chains was also found to facilitate the formation of an inter-residue lactone between the carboxyl group at the nonreducing terminal sulfated Neu5Ac and the hydroxyl group at C-9 of the penultimate Neu5Ac residue. The long chain base was 4-hydroxysphinganine (t18:0) and the major fatty acid species were identified as C20:1, C21:1, and C22:1.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    The protein journal 16 (1997), S. 469-479 
    ISSN: 1573-4943
    Keywords: Attomole sensitivity ; Q-TOF ; MHC antigens ; peptide sequencing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Ultra-high-sensitivity, biopolymer sequencing is a goal in many fields of molecular biology, and collisionally activated decomposition electrospray mass spectrometry (CAD ES MS/MS) using a triple quadrupole mass spectrometer has become a method of choice for work in the high- to mid-femtomole range. However, when the detection of ions becomes statistical, as it may in that range, the mass assignment of fragment ions is inaccurate and either sequencing becomes impossible or ambiguities result due, for example, to the closeness in amino acid residue masses (I/L, N or K/Q, E). Some ambiguities may be resolved by synthesizing possible sequences, but this is unsatisfactory. In considering the limitations of triple quadrupole MS/MS with respect to scanning ion detection, resolution, transmission, and mass accuracy, we reasoned that a novel geometry quadrupole orthogonal acceleration time-of-flight (Q-TOF) instrument would have special merit for ultra-high-sensitivity MS/MS sequencing, and suggested its construction for this purpose some three years ago. A prototype Q-TOF has now been built by Micromass [Morris et al. (1996), Rapid Commun. Mass Spectrom. 10, 889–896], and in the first research on the instrument, including MHC antigen and filarial nematode glycoprotein studies, we demonstrate low-femtomole- and attomole-range sequencing with mass accuracy of better than 0.1 Da throughout the daughter-ion spectrum, thus removing sequencing ambiguities in some of the most challenging work demanding the highest sensitivity.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Two-sector linked-scan analysis of an unpurified proteolytic digest of a pyruvate decarboxylase enzyme (60 000 Da) has allowed the discovery and assignment of an amino-terminal post-translational modification and processing event. A difference in amino acid sequence from that predicted by a recently published nucleotide sequence has also been found. These results illustrate both the use and considerable potential of linked-scan methods for the analysis of complex biopolymer mixtures.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Developmental Genetics 9 (1988), S. 579-587 
    ISSN: 0192-253X
    Keywords: DIF ; Cyclic AMP ; Br-cyclic AMP ; pattern-formation ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The major inducers of cell differentiation in Dictyostelium appear to be cyclic AMP and DIF-1. Recently we have chemically identified DIF-1, together with the closely related DIF-2 and -3. They represent a new chemical class of potent effector molecules, based on a phenyl alkanone with chloro, hydroxy, and methoxy substitution of the benzene ring. Previous work has shown that DIF-1 can induce prestalk-specific gene expression within 15 min, whereas it suppresses prespore differentiation. Hence, DIF-1 can control the choice of pathway of cell differentiation in Dictyostelium and is therefore likely to be involved in establishing the prestalk/prespore pattern in the aggregate. In support of this, we show that DIF treatment of slugs results in an enlarged prestalk zone. Cyclic AMP seems less likely to have such a pathway-specifie role, but later in development it becomes inhibitory to stalk cell differentiation. This inhibition may be important in suppressing terminal stalk cell differentiation until culmination.Spore differentiation can be induced efficiently by high levels of Br-cyclic AMP, a permeant analogue of cyclic AMP. In this, it phenocopies certain spore-maturation mutants, and we propose that during normal development spore differentiation is triggered by an elevation in intracellular cyclic AMP levels. How this elevation in cyclic AMP levels is brought about is not known. The experiments with Br-cyclic AMP also provide the first direct evidence that elevated levels of intracellular cyclic AMP induce differentiation in Dictyostelium.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 8 (1981), S. 463-473 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The development of a high field magnet for high mass electron impact, chemical ionization, field desorption and fast atom bombardment mass spectrometric studies is described. Its utility is illustrated with examples from structural studies of vitamin B12 biosynthetic intermediates, oligosaccharides, glycopeptides and the bleomycin antibiotics. The technique has also greatly assisted sequence studies of protein derived peptides.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 16 (1988), S. 353-355 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The morphogen, DIF-1, from Dictyostelium discoideum has recently been characterized as 1-(3,5-dichloro-2,6-dihydroxy-4-methoxyphenyl)-1-hexanone. Two related differentiation-inducing factors, DIF-2 and DIF-3, have been identified as the butyl ketone and monochloro analogues of DIF-1, respectively. These substances together with a number of structural analogues have been synthesized and subsequently analysed by mass spectrometry and bioassay.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 1 (1974), S. 269-273 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An azurin, a small respiratory copper protein from the bacterium Pseudomonas fluorescens biotype G, has been studied by mass spectrometry to determine sequence information. The study of homologously related proteins by mass spectiometry is particularly attractive, since the correct nature of major parts of the deduced sequences can be confirmed by comparison with the sequences of the protein from related organisms. An oxidized tryptohan residue has been identified amongst the products from a cyanogen bromide digest of this wild type azurin. In the same digest, a product is also found to arise from cleavage of the peptide chain at the C-terminal side of the same tryptophan residue. These results are rationalized.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 8 (1981), S. 128-136 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Low resolution electron impact mass spectrometry has been used as a major tool in the sequencing of a chloramphenicol acetyltransferase (mol. wt 25 668). Mass spectrometric data from mixtures of peptides from elastase, chymotryptic and subtilisin digests have defined 83% of the protein sequence. Several, previously unrecognized, peptide fragmentation pathways are reported.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 16 (1988), S. 191-195 
    ISSN: 1052-9306
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Protein structure determination of genetically engineered α1-antitrypsin was carried out using the technique of ‘fast atom bombardment (FAB) MAPPING’. CNBr, tryptic and chymotryptic FAB MAPS were produced. The anticipated amino terminal region of the molecule was not mapped at the expected mass, raising the possibility of post-translational modification. A specific experiment was designed to isolate and identify this region by FAB mass spectral screening of high-performance liquid chromatography separated peptides. A signal at m/z 1231 was observed which could not be assigned to any sequence in the molecule using the computer program. Following CNBr treatment, this signal disappeared completely, giving rise to a new signal at m/z 1058. The amino terminus was thus found to be extended by the presence of an N-acetyl methionine residue, and this discovery is the subject of the present paper; another modification within the sequence will be reported elsewhere. Combining the FAB MAPPING data, the overall structural confirmation achieved was 93% of the recombinant α1-antitrypsin molecule.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 328 (1987), S. 811-814 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Experiments of more than 50 years ago on amphibian embryos showed that the fate of a developing cell could be totally altered merely by transplanting it to a different part of the embryo. It is widely believed that this position-dependent development must reflect the existence of localized ...
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