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1.
P Nanda Devi C Sasikala C V Ramana 《Journal of industrial microbiology & biotechnology》2000,24(3):219-221
Rhodobacter sphaeroides OU5 transformed anthranilate (2 mM) to an indole (0.7 mM) in a light-dependent process. Photobiotransformation was enhanced
by tricarboxylic acid cycle intermediates and the indole formed was identified as 2,3 dihydroxy indole. Journal of Industrial Microbiology & Biotechnology (2000) 24, 219–221.
Received 16 September 1999/ Accepted in revised form 20 December 1999 相似文献
2.
Purification and characterization of rat-liver 3,4-dihydroxyphenylalanine decarboxylase 总被引:1,自引:0,他引:1
A simple and rapid procedure, which takes advantage of the effectiveness of conventional and HPLC hydrophobic interaction, for the isolation of highly purified rat liver 3,4-dihydroxyphenylalanine decarboxylase is described in detail. Some of its structural and functional properties are reported and discussed in comparison with those of pig kidney 3,4-dihydroxyphenylalanine decarboxylase. 相似文献
3.
Rhodobacter sphaeroides OU5 grows phototrophically with generation doubling time of 18 h on l-phenylalanine when used as sole source of nitrogen. Phenols accumulated in the medium and gallate (0.5 mM) was identified
as one of the major product. The others namely protocatechuate (0.2 mM) and caffeate (0.1 mM) and also three putative phenol
alkyl esters were identified using Liquid chromatography–mass spectroscopy (LC–MS) analysis from the culture supernatant.
Rhodobacter sphaeroides OU5 strain could explain its capability to produce the bioactive compounds during the growth. This study sheds production
of bioactive and their biological exploring molecules. 相似文献
4.
Sunayana MR Sasikala Ch Ramana ChV 《Journal of industrial microbiology & biotechnology》2005,32(2):41-45
Culture supernatants of Rhodobacter sphaeroides OU5 grown in the presence of 2-aminobenzoate gave an orange-red color-reaction with Salpers reagent, suggesting the presence of an indole derivative. This production was light-dependent and inducible only with 2-aminobenzoate. Replacement of 2-aminobenzoate with other 2-substituted benzoates did not result in the formation of indole. Fumarate appeared to be the conjugating molecule with 2-aminobenzoate, resulting in the formation of an indole derivative. The purified indole derivative was orange-brown in color, with a yields 0.34 mM from 1 mM 2-aminobenzoate. Infrared analysis suggested an indole ester and 1H NMR analysis indicated an indole carboxylate, esterified with a terpenoid alcohol. The indole ester has a mass of 441 with the molecular formula C27H39NO4. The IUPAC name of the compound is (3 E,5 E)-14-hydroxy-3,7,11-trimethyl-3,5-tetradecadienyl 2-(hydroxymethyl)-1 H-indole-3-carboxylate; and the common name given to this compound is sphestrin. 相似文献
5.
C B Voltattorni A Minelli P Vecchini A Fiori C Turano 《European journal of biochemistry》1979,93(1):181-188
A procedure for 3,4-dihydroxyphenylalanine decarboxylase from pig kkdney purification is described in detail. The preparation has no detectable impurity on electrophoresis and on ultracentrifugation and authors. However two significant differences are observed: a different stimulation of activity by added pyridoxal 5'-phosphate and a nearly complete decarboxylation of L-3,4-dihydroxyphenylalanine in absence of added coenzyme. Absorption, fluorescence and circular dichroism properties of the coenzyme-apoenzyme interaction are also described. The results are consistent with the existence of at least four coenzyme-apoenzyme complexes, three of them active. 相似文献
6.
N Rajasekhar C Sasikala C V Ramana 《Journal of industrial microbiology & biotechnology》1998,20(3-4):177-179
A purple non-sulfur anoxygenic phototrophic bacterium, Rhodobacter sphaeroides OU5 was able to photobiotransform indole in the presence of various organic substrates to its value-added derivatives tryptophan,
tryptamine, indole lactic acid and indigo, which are of high commercial value. The product formed varied with the precursors
provided in the medium.
Received 21 August 1997/ Accepted in revised form 10 January 1998 相似文献
7.
Acyl carrier protein (ACP) has been purified from the facultative phototrophic bacterium Rhodobacter sphaeroides. The ACP preparation was greater than 95% homogeneous as determined by native and disodium dodecyl sulfate (Na2DodSO4)-polyacrylamide gel electrophoreses and N-terminal amino acid analysis. Amino acid compositional analysis revealed that the protein contains approximately 75 amino acids, has a calculated minimum molecular weight of 8700, and lacks the amino acids tyrosine and tryptophan. The presence of the characteristic 4'-phosphopantetheine prosthetic group was indicated by the occurrence of equimolar quantities of beta-alanine and taurine in amino acid hydrolysates and was confirmed by independent chemical analysis. The protein displayed a pI of 3.8 and had a calculated partial specific volume of 0.732 mL/g. The primary structure of the protein has been determined for the first 46 amino acid residues from the N terminus of the molecule, and the region of the molecule encompassing the amino acids from residues 31 to 44 was found to have 100% homology with the identical residues in Escherichia coli ACP. In contrast to E. coli ACP, R. sphaeroides ACP migrated according to its molecular weight during Na2DodSO4 gel electrophoresis, was resistant to pH-induced denaturation, and comigrated with the cis-vaccenoyl-ACP derivative during native gel electrophoresis. It is proposed that the basis for these properties is the enhanced hydrophobic character of the protein. 相似文献
8.
Kobayashi K Saitoh T Shah DS Ohnishi K Goodfellow IG Sockett RE Aizawa SI 《Journal of bacteriology》2003,185(17):5295-5300
Flagellar hook-basal body (HBB) complexes were purified from Rhodobacter sphaeroides. The HBB was more acid labile but more heat stable than that of Salmonella species, and protein identification revealed that HBB components were expressed only from one of the two sets of flagellar gene clusters on the R. sphaeroides genome, under the heterotrophic growth conditions tested here. 相似文献
9.
浑球红假单胞菌菌株601经超声击碎,粗提液通过Triton处理,硫酸铵沉淀,DE—52和DEAE—sephadex A—50柱层析及 Seqhadex G—200凝胶过滤等步骤,将谷氨酸合酶(GOGAT)分离纯化,在聚丙烯酰胺凝胶电泳上呈现一条带。GOGAT表观分子量约为138 kD。该酶最大光吸收在278,375,450 nm和475 nm处,表明GOGAT可能是一种黄素蛋白。纯化的GOGAT对其底物 Gln,α—酮戊二酸和NADPH的表观K_m值分别为830,150和6μmol/L。反应产物Gln和NADP,几种氨基酸对GOGAT活力有不同程度的抑制作用,Gln类似物DON对GOGAT活力有强烈的抑制作用。 相似文献
10.
Shanker V Rayabandla SM Kumavath RN Chintalapati S Chintalapati R 《Current microbiology》2006,52(6):413-417
In an attempt to understand the aromatic hydrocarbon metabolism by purple bacteria that do not grow at their expense, we earlier
reported 2-aminobenzoate transformation by a purple non-sulfur bacterium, Rhodobacter sphaeroides OU5 (Sunayana et al., 2005, J Ind Microbiol Biotech 32:41–45), which is extended in the present study with aniline, a major
environmental pollutant. Aniline did not support photo (light anaerobic) or chemo (dark aerobic) heterotrophic growth of Rhodobacter sphaeroides OU5 either as a sole source of carbon or nitrogen. However, light-dependent aniline transformation was observed in the culture
supernatants and the products were identified as indole derivatives. The transformation was dependent on a tricarboxylate
intermediate, fumarate. Five intermediates of the aniline biotransformation pathway were isolated and identified as indole
esters having a mass of 443, 441, 279, 189, and 167 with unstoichiometric total indole yields of 0.16 mM from 5 mM of aniline consumed. The pathway proposed based on these intermediates suggest a novel xenobiotic detoxification process
in bacteria. 相似文献
11.
Two heat-shock proteins that show high identity with the Escherichia coli chaperonin 60 (groEL) and chaperonin 10 (groES) chaperonin proteins were purified and characterized from photolithoautotrophically grown Rhodobacter sphaeroides. The proteins were purified by using sucrose density gradient centrifugation and Mono-Q anion-exchange chromatography. In the presence of 1 mM ATP, the chaperonin 10 and chaperonin 60 proteins bound to each other and comigrated as a large complex during sucrose density gradient centrifugation. The native molecular weights of each protein as determined by gel filtration chromatography were 889,200 for chaperonin 60 and 60,000 for chaperonin 10. Chaperonin 60 is comprised of monomers with a molecular weight of 61,000 and chaperonin 10 is comprised of monomers with a molecular weight of 12,700 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Chaperonin 60 was 9.3% of the total soluble cell protein during photolithoautotrophic growth which increased to 28.5% following heat-shock treatment. When cells were grown photoheterotrophically or chemoheterotrophically, chaperonin 60 was reduced to 6.7% and 3.5%, respectively, of the total soluble protein. The N-terminal amino acid sequence of each protein was determined; chaperonin 60 of R. sphaeroides showed 72% identity to E. coli chaperonin 60 protein, and R. sphaeroides chaperonin 10 showed 45% identity with E. coli chaperonin 10. R. sphaeroides chaperonin 60 catalyzed ATP hydrolysis with a specific activity of 134 nmol min-1 mg-1 (kcat = 0.13 s-1) and was inhibited by R. sphaeroides chaperonin 10, but not E. coli chaperonin 10. The E. coli chaperonin 60 ATPase activity was inhibited by chaperonin 10 from both R. sphaeroides and E. coli. 相似文献
12.
13.
When challenged with reactive oxidants, the nonsulfur phototrophic bacterium Rhodobacter sphaeroides ATH 2.4.1 exhibited an oxidative stress response during both phototrophic and chemotrophic growth. Upon preincubation with
100 μM H2O2, catalase activity increased fivefold. Catalase was also induced by other forms of oxidative stress, heat-shock, ethanol
treatment, and stationary-phase conditions. Only one band of catalase activity was detected after native and denaturing PAGE.
The enzyme was purified 304-fold with a yield of 7%. The purified enzyme displayed a heterodimeric structure with subunits
of 75 and 68 kDa, corresponding to a molecular mass of approximately 150 kDa for the native enzyme. The subunits had almost
identical amino-terminal peptide sequences, sharing substantial similarity with other bacterial catalases. The enzyme exhibited
an apparent K
m of 40 mM and a V
max of 285,000 U (mg protein)–1. Spectroscopic analysis indicated the presence of protoheme IX. The heme content calculated from pyridine hemochrome spectra
was 0.43 mol per mol of enzyme. The enzyme had a broad pH optimum and was inhibited by cyanide, azide, hydroxylamine, 2-mercaptoethanol,
and sodium dithionite. These data indicate that this catalase belongs to the class of monofunctional catalases.
Received: 15 October 1997 / Accepted: 2 February 1998 相似文献
14.
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16.
A polyol dehydrogenase was detected in cell extracts of the facultative phototrophic bacterium Rhodobacter sphaeroides strain Si 4 grown on D-glucitol (sorbitol) as the sole carbon source. The enzyme was purified 150-fold to apparent homogeneity by steps involving fractionated (NH4)2SO4 precipitation, chromatography on Q-Sepharose and phenyl-Sepharose, and FPLC on Superose 12. The relative molecular mass (Mr) of the native polyol dehydrogenase was 47,200 as calculated from its Stokes' radius (rs = 2.76 nm) and sedimentation coefficient (s20, w = 4.15 S). SDS/PAGE resulted in one single band representing a polypeptide with a Mr of 52,200, indicating that the native protein is a monomer. The isoelectric point of the polyol dehydrogenase was determined to be pH 4.3. The enzyme was specific for NAD+ and oxidized both D-glucitol and D-mannitol to D-fructose, as well as D-arabinitol to D-ribulose. The pH optimum of substrate oxidation was pH 9.0 in 0.1 M Tris/HCl and that of substrate reduction was pH 6.5 in 0.1 M potassium phosphate. The reactions exhibited normal Michaelis-Menten kinetics allowing the estimation of KM values for NAD+ (0.18 mM) in the presence of D-glucitol, and for D-glucitol (31.8 mM), D-mannitol (0.29 mM) and D-arabinitol (1.8 mM), respectively. The KM value for D-fructose was 16.3 mM and that for NADH 0.02 mM. The equilibrium constants determined for the conversion of D-mannitol, D-glucitol and D-arabinitol were 4.5 nM, 0.58 nM and 80 pM, respectively. Based on the catalytic preference of the polyol dehydrogenase for D-mannitol, an enzymatic assay for D-mannitol was elaborated. 相似文献
17.
Isolation and characterization of the nifUSVW-rpoN gene cluster from Rhodobacter sphaeroides.
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The rpoN gene from Rhodobacter sphaeroides was isolated from a genomic library via complementation of a Rhodobacter capsulatus rpoN mutant. The rpoN gene was located on a 7.5-kb HindIII-EcoRI fragment. A Tn5 insertion analysis of this DNA fragment showed that a minimal DNA fragment of 5.3 kb was required for complementation. Nucleotide sequencing of the complementing region revealed the presence of nifUSVW genes upstream from rpoN. The rpoN gene was mutagenized via insertion of a gene encoding kanamycin resistance. The resulting rpoN mutant was not impaired in diazotrophic growth and was in all respects indistinguishable from the wild-type strain. Southern hybridizations using the cloned rpoN gene as a probe indicated the presence of a second rpoN gene. Deletion of the nifUS genes resulted in strongly reduced diazotrophic growth. Two conserved regions were identified in a NifV LeuA amino acid sequence alignment. Similar regions were found in pyruvate carboxylase and oxaloacetate decarboxylase. It is proposed that these conserved regions represent keto acid-binding sites. 相似文献
18.
EPR characteristics of cytochrome c1, cytochromes b-565 and b-562, the iron-sulfur cluster, and an antimycin-sensitive ubisemiquinone radical of purified cytochrome b-c1 complex of Rhodobacter sphaeroides have been studied. The EPR specra of cytochrome c1 shows a signal at g = 3.36 flanked with shoulders. The oxidized form of cytochrome b-562 shows a broad EPR signal at g = 3.49, while oxidized cytochrome b-565 shows a signal at g = 3.76, similar to those of two b cytochromes in the mitochondrial complex. The distribution of cytochromes b-565 and b-562 in the isolated complex is 44 and 56%, respectively. Antimycin and 2,5-dibromo-3-methyl-6-isopropyl-1,4-benzoquinone (DBMIB) have little effect on the g = 3.76 signal, but they cause a slight downfield and upfield shifts of the g = 3.49 signal, respectively. 5-Undecyl-6-hydroxyl-4,7-dioxobenzothiazole (UHDBT) shifts the g = 3.49 signal downfield to g = 3.56 and sharpens the g = 3.76 signal slightly. Myxothiazol causes an upfield shift of both g = 3.49 and g = 3.76 signals. EPR characteristics of the reduced iron-sulfur cluster in bacterial cytochrome b-c1 complex are: gx = 1.8 with a small shoulder at g = 1.76, gy = 1.89 and gz = 2.02, similar to those observed with the mitochondrial enzyme. The gx = 1.8 signal decreased and the shoulder increased concurrently as the redox potential decreased, indicating that the environment of the iron-sulfur cluster is sensitive to the redox state of the complex. UHDBT sharpens the gz and and shifts it downfield from g = 2.02 to 2.03, and shifts gx upfield from g = 1.80 to 1.78. UHDBT also causes an upfield shift of gy but to a much lesser extent compared to the other two signals. Addition of DBMIB causes a downfield shift of the gy from 1.89 to 1.94 and broadens the gx signal with an upfield to g = 1.75. Myxothiazol and antimycin show little effect on the gy and gz signals, but they broaden and shift the gx signal upfield to g = 1.74. However, the myxothiazol effect is partially reversed by UHDBT. An antimycin-sensitive ubisemiquinone radical was detected in the cytochrome b-c1 complex. At pH 8.4, the antimycin-sensitive ubisemiquinone radical has a maximal concentration of 0.66 mol per mol complex at 100 mV.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
19.
R S Nunn P J Artymiuk P J Baker D W Rice C N Hunter 《Journal of molecular biology》1992,228(4):1259-1262
The LH1 light harvesting complex has been purified from a mutant of the photosynthetic bacterium Rhodobacter sphaeroides which synthesizes LH1 as the sole pigment protein. Crystallization trials using polyethylene glycol as the precipitant in the presence of the detergent n-octyl glucoside have resulted in the formation of needle like crystals which diffract beyond 3.5 A and which are relatively resistant to radiation damage. X-ray photographs have established that the crystals belong to the tetragonal system and are probably in space group P4(2)2(1)2. Estimates of the crystal density indicate that the asymmetric unit of the crystals contains two oligomers each with an alpha 6 beta 6 stoichiometry. 相似文献
20.
Adenosine deaminase (ADA) was isolated from small intestine of mice and purified to utmost homogeneity. SDS-PAGE of purified ADA gave a molecular weight of 41 kDa. Western blot analyses gave a single reactive band at 41 kDa and the other band was an associated ADA binding protein. The purified enzyme was more stable in the alkaline pH. The optimum pH and the pI values were about 7.0 and 4.96, respectively. Km values of the small intestinal ADA for adenosine and 2-deoxyadenosine were 23 and 16M, respectively. Purine riboside was a competitive inhibitor with Ki of 5 M, whereas 2-3-o-isopropylidene adenosine acted as an uncompetitive inhibitor (Ki 66 M). Activity of ADA was inhibited by the presence of theophylline (-40%), caffeine (-30%), and L-cysteine (-50%). Significantly, Hg2+ (100 M) inhibited 98% of the initial ADA activity. In addition, various purine analogs such as inosine, purine, -adenosine and adenine showed variable inhibitions on the activity of ADA. Relative ADA activity towards 3-deoxyadenosine and 6-chloropurine riboside was lower by 30% and 40%, respectively. However, the activity towards 2-o-methyl adenosine was higher (30%) compared to the activity obtained using adenosine. 相似文献