共查询到20条相似文献,搜索用时 46 毫秒
1.
Sachio Hayashi Takenobu Yoshiyama Norito Fujii Satoru Shinohara 《Biotechnology letters》2000,22(18):1465-1469
A novel syrup containing neofructo-oligosaccharides was produced from sucrose (Brix 70) by whole cells of Penicillium citrinum. The efficiency of fructo-oligosaccharides production was more than 55% and those of the main carbohydrate components, 1-kestose (Fruf 21Fruf 21 Glc), nystose (Fruf 21Fruf 21 Fruf 21 Glc) and neokestose (Fruf 26 Glc12 Fruf), were 22, 14 and 11%, respectively. 相似文献
2.
Takatani M Nakama T Kubo K Manabe S Nakahara Y Ito Y Nakahara Y 《Glycoconjugate journal》2000,17(6):361-375
As part of a program to explore the structural requirement of N-glycans in the carbohydrate-mediated biological interactions, N-linked pentasaccharide core structure was stereochemically modified in terms of glycosidic linkage. Three isomers, -D-Man-(13)-[-D-Man-(16)]--D-Man-(14)--D-GlcNAc-(14)--D-GlcNAc-L-Asn, -D-Man-(13)-[-D-Man-(16)]--D-Man-(14)--D-GlcNAc-(14)--D-GlcNAc-L-Asn, and -D-Man-(13)-[-D-man-(16)]--D-Man-(14)--D-GlcNAc-(14)--D-GlcNAc-L-Asn, were synthesized. Synthesis of the pentasaccharide with natural linkage is also described. 相似文献
3.
Yoshioka Katsuji Furuya Hirokazu Sasaki Hiroyuki Saraiva Maria Joao Mascarenhas Costa Pedro P. Sakaki Yoshiyuki 《Human genetics》1989,82(1):9-13
Summary Familial amyloidotic polyneuropathy (FAP) is an autosomal dominant genetic disease characterized by systemic accumulation of amyloid fibrils. A major component of FAP anyloid has been identified as variant transthyretin (TTR, also called prealbumin). In particular, a variant with the substitution 30ValMet has been commonly found in FAP of various ethnic groups. To understand the origin and spread of the ValMet mutation, we analyzed DNA polymorphisms associated with the TTR gene in six Japanese FAP families and several Portuguese FAP patients. Three distinct haplotypes associated with the ValMet mutation were identified in Japanese FAP families, one of which was also found in Portuguese patients. On the other hand, it was found that the ValMet mutation can be explained by a C-T transition at the CpG dinucleotide sequence of a mutation hot spot. Thus, our findings indicate that the ValMet mutation has probably recurred in the human population, to generate FAP families of independent origin. 相似文献
4.
Production of an extracellular polysaccharide byAgrobacterium sp DS3 NRRL B-14297 isolated from soil
Dr. C T Hou J A Ahlgren W Brown J J Nicholson 《Journal of industrial microbiology & biotechnology》1996,16(2):129-133
A bacterium isolated from soil and identified asAgrobacterium sp produced a water-soluble extracellular polysaccharide capable of producing highly viscous solutions. Gas chromatographic analysis revealed a sugar composition of glucose, galactose and mannose in the molar ratio of 7.52.41, together with 3.7% (w/w) pyruvic acid. Methylation analyses showed the presence of (13)-, (14)- and (16)-linked glucose, (13)- and (14, 16)-linked galactose and a small portion of (13)-linked mannose residues. Succinic acid was not present. The molecular weight of the polysaccharide was estimated by light scattering to be 2×106 Da. The viscosity of solutions containing the polysaccharide remained constant from pH 3 to 11, and decreased by 50% when heated from 5 to 55°C. Maximum yield of the polysaccharide, 20 g L–1, was reached in 48 h at 30°C incubation. 相似文献
5.
A new -glucosidase was partially purified from Trichoderma viride cellulase. This -glucosidase catalyzed a transglycosylation reaction of cellobiose to give -D-Glc-(16)--D-Glc-(14)-D-Glc (1, yield: 18.8%) and -D-Glc-(16)--D-Glc-(16)--D-Glc-(14)-D-Glc (2, 3.7%), regioselectively. Furthermore, the enzyme regioselectively converted laminaribiose and gentiobiose into -D-Glc-(16)--D-Glc-(13)-D-Glc (3, 15.3%) and -D-Glc-(16)--D-Glc-(16)-D-Glc (4, 20.2%), respectively. The structures (1–4) of the products were determined by 1H and 13C NMR spectroscopies. This high regio- and stereoselectively of the -glucosidase could be applied for oligosaccharide synthesis. 相似文献
6.
Summary A balanced translocation was found in a normal female with a history of four abortions. On the basis of the Giemsa-banding pattern the abnormality was interpreted as to be a translocation of a part of the long arm of chromosome 13 to the short arm of chromosome 7:t(7;13)(7qter7p22::13q1413qter;13q1413pter::7p227pter). Problems in genetic counseling are discussed with respect to this case.Supported by the Forschungsprojekt Medizinische und soziale Probleme der menschlichen Reproduktion des Ministeriums für Gesundheitswesen der DDR. 相似文献
7.
Herrouin M Mollé D Fauquant J Ballestra F Maubois JL Léonil J 《Journal of Protein Chemistry》2000,19(2):105-116
Novel genetic variants for donkey milk lysozyme and -lactoglobulins I and II have been identified by the combined use of peptide mass mapping and sequencing by tandem mass spectrometry in association with database searching. The novel donkey lysozyme variant designated as lysozyme B (Mr 14,631 Da) differed in three amino acid exchanges, N49 D, Y52 S, and S61 N, from the previously published sequence. Three novel genetic variants for donkey -lactoglobulins were identified. One of them is a type -lactoglobulin I with three amino acid exchanges at E36 S, S97 T, and V150 I (-lactoglobulin I B, Mr 18,510 Da). The two others are type -lactoglobulins II with two amino acid exchanges at C110 P and M118 T (-lactoglobulin II B, Mr 18,227 Da) and with three amino acid exchanges at D96 E, C110 P, and M118 T (-lactoglobulin II C, Mr 18,241 Da). All these primary structures are closely related to those of homologous proteins in horse milk (percent identity >96%). 相似文献
8.
Point mutations in the upstream region of the α-galactosidase A gene exon 6 in an atypical variant of Fabry disease 总被引:5,自引:0,他引:5
Summary Single point mutations in the upstream region of exon 6 of the -galactosidase A gene were found in two Japanese cases of the cardiac form of Fabry disease; 301ArgGln (902GA) in a case that has already been published and 279GlnGlu (835CG) in a new case. They both expressed markedly low, but significant, amounts of residual activity in COS-1 cells. In contrast, two unrelated cases with classic Fabry disease were found to have different point mutations, which showed a complete loss of enzyme activity in a transient expression assay; 328GlyArg (982GA) in the downstream region of exon 6 in one case and two combined mutations, 66GluGln (196GC)/112ArgCys (334CT), in exon 2 in the other. We conclude, on the basis of the results recorded in this study and those in previous reports, that the pathogenesis of atypical Fabry disease is closely associated with point mutations in the upstream region of exon 6 of the -galactosidase A gene. 相似文献
9.
Enis Boletini Martina Svobodova Vladimir Divoky Erol Baysal Mehmet A. Cürük Aleksandar J. Dimovski Rong Liang Adekunle D. Adekile Titus H. J. Huisman 《Human genetics》1994,93(2):182-187
We have analyzed the hemoglobin abnormalities in nearly 50 Albanian patients with a significant hemoglobinopathy and included 37 relatives in this study. Sickle cell anemia (SS) is a common disorder; all 15 sickle cell anemia patients had the complications expected for this disease. The s haplotype was type 19 (Benin); -thalassemia-2 was rare. Three -thalassemia alleles (IVS-I-110, GA; codon 39, CT; IVS-I-6, TC) were present in nearly 85% of the -thalassemia alleles; their frequencies were intermediate between those observed in the populations of neighboring countries. A few rare mutations were also found, which might have originated in India, Turkey, Macedonia, and Greece. Nearly all patients with Hb S--thalassemia had the IVS-I-110 (GA) mutation. The frequencies of 11 -thalassemia mutations in 17 mostly Mediterranean countries have been reviewed. 相似文献
10.
Karel Indrak Vaclav Brabec Jarmila Indrakova Ladislav Chrobak Adriana Sakalova Marie Jarosova Jaroslav Cermak You-jun Fei Ferdane Kutlar Yuan-chao Gu Erol Baysal Titus H. J. Huisman 《Human genetics》1992,88(4):399-404
Summary We have identified different -thalassemia mutations in 93 members of 34 families of Czech or Slovakian descent using gene amplification, hybridization with specific 32P-labeled oligonucleotide probes, sequencing of amplified DNA, and gene mapping. The GA mutation at IVS-I-1 was found in 18 families; other Mediterranean mutations were IVS-II-1 (GA), IVS-II-745 (CG), IVS-I-110 (GA), and codon 39 (CT); these were present in 9 additional families. The GT mutation at codon 121, known to cause Heinzbody -thalassemia, was present in 3 families, and the frameshift at codons 82/83 (-G), first described in the Azerbaijanian population, in 2 families. A newly discovered allele was a frameshift at codons 38/39 (-C). One -thalassemia allele was incompletely characterized. We observed in 2 families a TC mutation at position +96 UTR (untranslated region) relative to the termination codon; this mutation likely is a rare polymorphism, -Thalassemia was rare; only one person carried the -3.7 heterozygosity, and one other had a yet to be identified -thalassemia-1, while seven had the anti 3.7 triplication. 相似文献
11.
A Hu-Barkana-Gruzinov cold dark matter scalarfield may enter a weak isospin invariant derivative interactionthat causes the flow of right-handed electrons to align parallelto (). Hence, in the outer regions of galaxies where () islarge, as in galactic halos, the derivative interaction mayinduce a chirality-imbued quantum chemistry. Such a chirality-imbued chemistry would in turn be conducive to the formation ofabundant precursor biopolymers on interstellar dust grains,comets and meteors in galactic halo regions, with subsequentdelivery to planets in the inner galactic regions where and() are concomitantly near zero and left-right symmetricterrestrial quantum chemistry prevails. 相似文献
12.
Pentobarbital stimulates 36Cl– permeation across single Deiters' membranes in a microchamber system, acting on classical, extracellularly facing, GABAA receptors. However, when applied on the membrane cytoplasmic side it activates per se labeled chloride inout permeation. No effect was found on chloride outin permeation. Similarly, at lower concentrations it facilitates the increase of 36Cl– inout permeation by application of GABA on the membrane inside, again via asymmetric chloride channels allowing inout but not outin passage. These data confirm that on the Deiters' membrane cytoplasmic side there are structures behaving pharmacologically as GABAA receptors whose function is that of a Cl– extrusion pump. This mechanism involves a cycle of activation-phosphorylation/desensitization-reactivation of the receptor complexes 相似文献
13.
George P. Patrinos Aphrodite Loutradi-Anagnostou Manoussos N. Papadakis 《Human genetics》1996,97(3):357-358
A new TA base substitution, identified inside the 5 regulatory region of the humanA globin gene (A –499 T A), is reported. This nucleotide change was found to be linked incis with the mutation producing sickle cell anemia (CD6 GAGGTG: s gene). 相似文献
14.
Werner Dangel Ruth Brackmann Achim Lack Magdy Mohamed Jürgen Koch Brigitte Oswald Birgit Seyfried Andreas Tschech Georg Fuchs 《Archives of microbiology》1991,155(3):256-262
The regulation of the expression of enzyme activities catalyzing initial reactions in the anoxic metabolism of various aromatic compounds was studied at the whole cell level in the denitrifying Pseudomonas strain K 172. The specific enzyme activities were determined after growth on six different aromatic substrates (phenol, 4-hydroxybenzoate, benzoate, p-cresol, phenylacetate, 4-hydroxyphenylacetate) all being proposed to be metabolized anaerobically via benzoyl-CoA. As a control cells were grown on acetate, or aerobically on benzoate. The expression of the following enzyme activities was determined.Phenol carboxylase, as studied by the isotope exchange between 14CO2 and the carboxyl group of 4-hydroxybenzoate; 4-hydroxybenzoyl-CoA reductase (dehydroxylating); p-cresol methylhydroxylase; 4-hydroxybenzyl alcohol dehydrogenase; 4-hydroxybenzaldehyde dehydrogenase; coenzymeA ligases for the aromatic acids benzoate, 4-hydroxybenzoate, phenylacetate, and 4-hydroxyphenylacetate; phenylglyoxylate: acceptor oxidoreductase and 4-hydroxyphenylglyoxylate: acceptor oxidoreductase; aromatic alcohol and aldehyde dehydrogenases.The formation of most active enzymes is strictly regulated; they were only induced when required, the basic activities being almost zero. The observed whole cell regulation pattern supports the postulate that the enzyme activities play a role in anoxic aromatic metabolism and that the compounds are degraded via the following intermediates: Phenol 4-hydroxybenzoate 4-hydroxybenzoyl-CoA benzoyl-CoA; 4-hydroxybenzoate 4-hydroxybenzoyl-CoA benzoyl-CoA; benzoate benzoyl-CoA; p-cresol 4-hydroxybenzaldehyde 4-hydroxybenzoate 4-hydroxybenzoyl-CoA benzoyl-CoA; phenylacetate phenylacetyl-CoA phenylglyoxylate benzoyl-CoA plus CO2; 4-hydroxyphenylacetate 4-hydroxyphenylacetyl-CoA 4-hydroxyphenylglyoxylate 4-hydroxybenzoyl-CoA plus CO2 benzoyl-CoA. 相似文献
15.
Summary Imidazolides of dinucleotides such as ImpApA can be formed from the corresponding dinucleotides in a two-stage process, which gives up to 15% yields under potentially prebiotic conditions. First a solution of the dinucleotide and sodium trimetaphosphate is dried out at constant temperature and humidity. This produces polyphosphates such as pnApA in excellent yield (80%). The products are dissolved in water, imidazole is added, and the solution is dried out again. This yields the 5-phosphorimidazolides.Abbreviations P3!
trimetaphosphate
- A
adenosine
- U
uridine
- EDTA
ethylenediaminetetraacetic acid
- Ap
adenosine 2(3)-phosphate
- Ap!
adenosine cyclic 2:3-phosphate
- pA
adenosine 5-phosphate
- pA2p
adenosine 2, 5-diphosphate
- pA3p
adenosine 3, 5-diphosphate
- pAp!
5-phospho-adenosine cyclic 2:3-phosphate
- ATP
adenosine 5-triphosphate
- ImpA
adenosine 5-phosphorimidazolide
- A2pA
adenylyl-[25]-adenosine
- A3pA
adenylyl-[35]-adenosine
- A2pU
adenylyl-[25]-uridine
- A3pU
adenylyl-[35]-uridine
- pA2pA
5-phosphoadenylyl-[25]-adenosine
- pA3pA
5-phospho-adenylyl-[35]-adenosine
- pA2pU
5-phospho-adenylyl-[25]-uridine
- pA3pU
5-phospho-adenylyl-[35]-uridine
- pApN (N= A, U)
5-phosphate of a dinucleoside phosphate
- pnApN (N = A, U; n = 2, 3, 4.)
5-polyphosphate of a dinucleoside phosphate
- ImpA2pA
imidazolide of pA2pA
- ImpA3pA
imidazolide of pA3pA
- ImpA2pU
imidazolide of pA2pU
- ImpA3pU
imidazolide of pA3pU
- ImpApN
imidazolide of pApN 相似文献
16.
Summary Direct sequencing of segments of the factor VIII gene in 30 hemophiliacs with sporadic disease (32+ kb of sequence in total) revealed two missense transitions: glutamate 1704 to lysine (E1704K) in a patient with severe hemophilia A and proline 2300 to serine (P2300S) in a patient with mild hemophilia. Both transitions are likely to be causative mutations because the amino acids affected were evolutionarily conserved. Haplotype and sequence analysis of the mother and grandparents of patient HA12 (E1704K) indicate that the mutation arose in the grandfather who was 27 years old when his daughter was conceived. The origin of mutation in patient HA39 (P2300S) could not be determined. As mutations that cause mild disease can be found in seemingly unrelated families, 96 unrelated hemophiliacs were screened rapidly for the P2300S mutation with polymerase chain reaction (PCR) amplification of specific alleles (PASA). None of these patients had the mutation. PASA was also used to conveniently assess a polymorphic site in intron 7. The polymorphism is estimated to be informative in 13% of Korean females and in 23% of Western European females. 相似文献
17.
A specific 1,2-a-mannosidase from A. phoenicis was immobilised on China clay, cellulose DE-52 and by entrapment in sodium alginate beads with respective yields of 19%, 16% and 18% in synthesis reactions consisting of 80% (w/w) mannose. Mana16man was the predominant product with China clay- and DE-52-immobilised enzymes with lesser amounts of mana12 and mana13. With the alginate bead-immobilised enzyme, mana12 was the predominant linkage formed. 相似文献
18.
As part of the multicenter project entitled Pathobiological Determinants of Atherosclerosis in Youth (PDAY), we are testing polymorphisms in candidate genes of atherosclerosis and hypertension for associations with arterial lesions in autopsied young persons. In this study, we used temperature gradient gel electrophoresis (TGGE) to type the Met235Thr polymorphism in exon 2 of the angiotensinogen gene (AGT) that is associated with essential hypertension in some human populations. In addition to Met235Thr, we detected and sequenced four other TGGE variants in exon 2 of AGT. These included two new amino acid substitutions (Thr209 Ile and Leu211Arg) that were found only among black PDAY cases. The frequency of the Ile209 mutation was 0.002 and the frequency of the Arg211 was 0.006 in 260 black PDAY cases. The other two TGGE variants were Tyr248Cys and a TC substitution at nucleotide position 171 that had been identified in previous studies. We also developed restriction isotyping for rapid typing of each AGT variant using PCR amplification and digestion with diagnostic restriction enzymes. 相似文献
19.
Nabedryk Eliane Breton Jacques Okamura Melvin Y. Paddock Mark L. 《Photosynthesis research》1998,55(2-3):293-299
In bacterial reaction centers (RCs), changes of protonation state of carboxylic groups, of quinone-protein interactions as well as backbone rearrangements occuring upon QB photoreduction can be revealed by FTIR difference spectroscopy. The influence of compensatory mutations to the detrimental Asp L213 Asn replacement on QB
–/QB FTIR spectra of Rb. sphaeroides RCs was studied in three double mutants carrying a Asn M44 Asp, Arg M233 Cys, or Arg H177 His suppressor mutation. The proton uptake by Glu L212 upon QB
– formation, as reflected by the positive band at 1728 cm–1, is increased in the Asn M44 Asp and Arg H177 His suppressor RCs with respect to native RCs, and remains comparable to that observed in Asp L213 Asn mutant RCs. Only the Arg M233 Cys suppressor mutation affected the 1728 cm–1 band, reducing its amplitude to near native level. Thus, there is no clear correlation between the apparent extent of proton uptake by Glu L212 and the recovery of the proton transfer RC function. In all of the mutant spectra, several protein (amide I and amide II) and quinone anion (C...O/C...C) modes are perturbed compared to the spectrum of native RCs. These IR data show that all of the compensatory mutations alter the semiquinone-protein interactions and the backbone providing direct evidence of structural changes accompanying the restoration of efficient proton transfer in RCs containing the Asp L213 Asn lesion. 相似文献
20.
Fumio Yatagai Jennifer A. Halliday Barry W. Glickman 《Molecular & general genetics : MGG》1991,230(1-2):75-80
Summary To investigate the impact of SOS induction on the distribution of spontaneous mutation, 111 recA441-mediated mutations were characterized at the DNA sequence level in the lacI gene of Escherichia coli. A 2.6-fold enhancement in lacI
– mutation frequency was observed after induction of the SOS system in the absence of mutagenic treatment, and specific classes of mutational events were induced. G : C C : G, G : C T : A and A : T T : A transversion events were specifically enhanced after SOS induction. A preferential 5-Y-Purine-3 neighbouring base specificity for these transversion events is reported here (normalised for mutation of the purine residue). In addition, a preference for transversion events at 5-C/GTGG-3 sequences is also observed. Fifty events were recovered at the lacI frameshift hotspot site and were equally represented by 4 bp addition and deletion events. This 1:1 ratio deviates significantly from the 4:1 distribution characteristic of spontaneous frameshift mutation in the RecA+ background and is a consequence of the fourfold induction of the (–)4 event. This abberrant distribution was confirmed by oligomeric probing of 474 independent recA441-mediated spontaneous lacI
– mutations. 相似文献