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1.
The conserved residue Thr42 of -subunit of the chloroplast ATP synthase of maize (Zea mays L.) was substituted with Cys, Arg, and Ile, respectively, through site-directed mutagenesis. The over-expressed and refolded -proteins were purified by chromatography on DEAE-cellulose and FPLC on mono-Q column, which were as biologically active (inhibiting Ca2+-ATPase activity and blocking proton gate) as the native subunit isolated from chloroplasts. The T42C and T42R showed higher inhibitory activities on the soluble CF1(–) Ca2+-ATPase than the WT. The T42I inhibited the Ca2+-ATPase activity of soluble CF1 and restored photophosphorylation activity of membrane-bound CF1 deficient in the most efficiently. Far-ultraviolet CD spectra showed that the portions of -helix and -sheet structures of the three mutants were somewhat different from WT. Thus the conserved residue Thr42 may be important for maintaining the structure and function of the -subunit and the basic functions of the -subunit as far as an inhibitor of Ca2+-ATPase and the proton gate are related. 相似文献
2.
Tatos Akopyan Anna Arzumanyan Hasmik Aghajanyan Ara Arutunyan Anahit Khanazadyan 《Neurochemical research》1986,11(1):47-53
Two fluorescent derivatives of substance P (SP) (Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH2) were prepared by chemical modification of the native peptide by pyridoxal-5-phosphate (pyridoxal-P). The formation of both pyridoxal-P-derivatives of SP is the result of one modification procedure. The determination of the amino acid composition showed that in one of the derivatives the -amino group of the Lys residue [-(P-pxy)-SP] and in the other the -amino group of the Lys residue and also the N-terminal amino group [,-di-(P-pxy)-SP] of SP had been substituted by pyridoxal-P. -(P-pxy)-SP and ,-di-(P-pxy)-SP have spasmogenic activity with ED50 of 1.8×10–9 and 4×10–9 M, respectively, tested on isolated guinea pig ileum. The fluorescence of P-pxy residues permits detection of as little as 1 pmol/ml of -(P-pxy)-SP and 0.5 pmol/ml of ,-di-(P-pxy)-SP. Both analogues of SP obtained are degraded by human plasma more slowly than the native peptide.Abbreviations SP
substance P
- pyridoxal-P
pyridoxal-5-phosphate
- P-pxy
phospho-pyridoxyl residue
- -(P-pxy)-SP
substance P modified by pyridoxal-P at the -amino group of the Lys residue
- ,-di-(P-pxy)-SP
substance P modified by pyridoxal-P at the -amino group of the Lys residue and the N-terminal amino group of SP
- (P-pxy)-Lys
Lys modified by pyridoxal-P at the -amino group 相似文献
3.
Korovaitseva G. I. Sherbatich T. V. Selezneva N. V. Gavrilova S. I. Golimbet V. E. Voskresenskaya N. I. Rogaev E. I. 《Russian Journal of Genetics》2001,37(4):422-427
Allele 4of the apolipoprotein E (APOE) gene is associated with higher risk for family or sporadic Alzheimer's disease (AD) in many, though not all, ethnic groups. The APOEallele and genotype frequency distributions were evaluated in 207 AD patients without vascular disorders, 62 AD patients with vascular disorders (combined AD), and 206 control individuals (ethnic Russians from the Russian population). The frequency of allele 4in patients with early-onset and late-onset AD was three times higher than in controls (P< 0.000001). The increase in the frequency of 4in mixed dementia cases over controls was somewhat less but still significant (P= 0.0019). Relative risk of AD in carriers of allele 4was five times higher than in carriers of alleles 2and 3(P< 0.000001). Allele 2showed evidence of a protective effect in the early-onset AD group (P= 0.015). These results suggest that APOEallele 4is a universal factor of early-onset, late-onset, and combined AD in ethnic Russians from Russia. 相似文献
4.
The Apolipoprotein E4 allele (Apo-4) is the major susceptibility gene for late onset Alzheimer Disease (AD) but epidemiological data suggest that the effect of this allele is modified in different individuals by genetic or environmental factors. Age and head injury are major non-genetic factors modifying the Apo-4 risk. There is conflicting data as to whether alleles of other chaperon proteins (such as alpha-1-antichymotrypsin (ACT)) or Apo-4 receptors (such as the VDRL receptor) modify the Apo-4 risk for AD. We analyze problems posed by genetic association studies including those of multiple comparisons and selection of controls, the latter problem exacerbated by the wide variations in Apolipoprotein E allele frequencies observed in different groups and localities. 相似文献
5.
We found that -caprolactam is a new powerful inducer for the formation of Rhodococcus rhodochrous J1 nitrilase. When Rhodococcus rhodochrous J1 cells were cultivated at 28°C for 120 h in a nutrient medium supplemented with 0.5% (w/v) -caprolactam, an enormous amount of nitrilase was formed in the cells which corresponded to approximately 30% of all soluble protein. The level of -caprolactam in the culture broth barely decreased in the course of cultivation. -Butyrolactam and -valerolactam also caused effective induction. The induction of nitrilase formation by -caprolactam was also observed in some other Rhodococcus strains. 相似文献
6.
In the present study of 9,000 individuals representative of the general population, we have considered whether the addition of common single nucleotide polymorphisms (SNPs) in the promoter region of Apolipoprotein E (APOE) improve the statistical explanation of variation in lipid traits and test the hypothesis that the estimated genotype effects are independent of factors indexed by gender and age. To address these questions, we have asked, for each gender and for each 20-year age strata (young: 20–39 years; middle-aged: 40–59 years; old: 60–79 years; very old: 80–100 years), how much trait variation is associated with the traditional 2, 3, and 4 allelic variations defined by the g.2059TC and g.2197CT SNPs in the fourth exon of the APOE gene, and how much additional trait variation is associated with genotypes defined by combining the g.2059TC and g.2197CT SNPs with one, two, or three promoter SNPs. Our study demonstrates that the pleiotropic effects of genotype variation defined by the traditional 2, 3, and 4 alleles on five plasma measures of lipid metabolism manifest differently in women and men and change significantly during the life cycle for high-density lipoprotein cholesterol in women. Multi-site genotypes defined by adding SNPs located in the 5 promoter region to the traditional g.2059TC and g.2197CT SNPs doubled the estimate of genetic variance of high-density lipoprotein and apolipoprotein Al in middle-aged females. 相似文献
7.
The paper presents a five-phase model to describe batch culture of Spirulina maxima under limitations of light and nutrients nitrogen andsulfur. The general equation for the exponential, linear, decelerating andstationary phases of the growth curve took into account that (i) the specificgrowth rate was proportional to the local light intensity in thephotobioreactor; (ii) light attenuation was due to cell's absorption andreflection and observed the Lambert-Beer's law with a total absorptioncoefficient (T) that was the sum of absorption coefficient(a) and reflection coefficient (r); (iii) thecomposition of the alga and its absorption a changed withtime and (iv) the specific growth rate was influenced by nutrients ofnitrogen and sulfur in the culture medium according to a Monod's law.Two successive equations describing the death phase were proposed basedon the hypothesis that the death rate accelerated with the %PSC until itreached its maximum. From that point the %PSC decreased and the deathrate reduced. Our model fitted very well the cultures grown in the photobioreactor developed in our laboratory. 相似文献
8.
Pomara Nunzio Shao Binbin Wisniewski Thomas Mehta Pankaj D. 《Neurochemical research》1998,23(12):1563-1566
This report examines plasma amyloid proteins A40 and A42 and apolipoprotein E (apoE) levels and their relationships with age in non-demented older adults with (N = 32) or without the apoE-4 allele (N = 94). A levels did not differ between the groups whereas the 4 allele was associated with a significant reduction in plasma apoE. In subjects with the 4 allele, increasing age was associated with significant reduction in plasma A40. Subjects without the 4 allele showed a significant positive correlation between A40 and A42 levels. There was also a significant correlation between plasma A40 and apoE levels in all subjects. 相似文献
9.
K. Riedel A. V. Naumov V. G. Grishenkov A. M. Boronin H. J. Stein F. Scheller H. -G. Mueller 《Applied microbiology and biotechnology》1989,31(5-6):502-504
Summary A microbial amperometric sensor using immobilized Pseudomonas putida cells was developed for the determination of -caprolactam. The cells contained plasmids encoding the -caprolactam degrading enzymes. A linear dependence of the electric current was obtained from 4 to 40 mol/l -caprolactam. The sensitivity for -caprolactam was one order of magnitude higher than that for its degradation products. The microbial sensor was stable for 21 days. 相似文献
10.
By Southern hybridization using a genomic DNA fragment carrying a human IgE heavy chain constant region gene (C
) as a probe, we analyzed the organization of human C
genes and their flanking regions in 23 atopic dermatitis and 6 senile erythroderma patients with elevated serum IgE levels, and 6 atopic dermatitis patients with normal IgE levels. On Barn HI, Hind III, and Eco RI digestions, we detected three hybridizable fragments containing three human C
genes, C
1, C
2, and C
3, respectively, in all leukocyte DNAs. These fragments were almost identical in size among patients and healthy donors. Pst I digestion generated a genetic polymorphism. We, however, could find no correlation between this polymorphism and the disorders. It was concluded that among the patients and healthy donors, there was no marked difference in the organization of the functional C
gene and its flanking region containing a class switch region. Our conclusion cannot rule out the presence of genetic abnormalities of this region in some atopic dermatitis patients which are not resolvable by our method. In the course of this study, we found a novel C
-like gene in placenta DNA which differs from the three C
genes commonly present in normal human DNA. 相似文献
11.
The synthetic peptides Gly5--Ahx and l-Ala3--Ahx, with structural similarity to the interpeptide bridge peptides of staphylococci or micrococci, respectively, were covalently linked to human serum albumin via their carboxylgroups. Antisera to these synthetic peptidyl-protein antigens contained fairly high amounts of antibodies with specificity to the N-terminal parts of the peptide chains attached to the carrier proteins. Antisera to (Gly5--Ahx)20-albumin gave, without exception, strong precipitin reactions in latex-agglutination with staphylococcal peptidoglycans. The antisera completely failed, however, in any reaction with peptidoglycans of micrococci or other bacteria which did not have these oligo-glycine peptides typical for staphylococci. On the contrary, antisera to (l-Ala3--Ahx)22-albumin strongly precipitated micrococcal peptidoglycans with oligo-l-alanine interpeptide bridges (e.g. Micrococcus varians, Micrococcus reseus), but showed no significant reaction with peptidoglycans of staphylococci or other bacteria lacking oligo-l-alanine interpeptide bridges.Abbreviations Use Ac
acetyl-
- -Ahx
-amino caproic acid
- ATCC
American Type Culture Collection, Rockville, Md., U.S.A.
- CCM
Czechoslovak Collection of Microorganisms, Brno, CSSR
- DSM
Deutsche Sammlung für Mikroorganismen, München, FRG
- IMRU
Institute of Microbiology, Rutgers University, N.J., U.S.A.
- Kiel
Bundesanstalt für Milchforschung, Kiel, FRG
- NPS
o-nitrophenylsulphenyl-
- -OMe
methyl ester
- -OSu
succinimide ester
- Z-
benzyloxycarbonyl 相似文献
12.
Summary Detection of (-glutamyl) lysine crosslinks is not only necessary for establishing the importance of the dipeptide as a post-translational modification of proteins, but provides information as to the importance of the transglutaminase enzyme in a biological system. The crosslink may be detected using both indirect and direct methodology. Indirect methods for its detection include measurement of masked lysines within a protein, detection of polymer formation by gel-electrophoresis and the inhibition of crosslinking by the incorporation of small molecular weight amines into the substrate protein. Direct methods for the detection of (-glutamyl) lysine require the actual isolation of the dipeptide following its release from the sample protein by exhaustive proteolytic digestion. Separation of the dipeptide from other components of the digest may be achieved by either ion-exchange chromatography or gel filtration and its qualitative identification achieved by techniques such as paper-electrophoresis or thin layer chromatography. Quantitative estimation of (-glutamyl) lysine normally involves its further separation by ion-exchange chromatography and its post-column detection following derivatisation with ninhydrin. More recent techniques include pre-column derivatisation of the dipeptide with fluorogenic reagents such as -pthalaldehyde and separation by reverse phase HPLC. With the recent advances in liquid chromatography resulting in the improved resolution of amino acids, increased sensitivity, rapid analysis times, and small sample sizes, it appears likely that direct quantitation of (-glutamyl) lysine will be the preferred method for the future. 相似文献
13.
G. P. Vlasov V. I. Korol'kov G. A. Pankova I. I. Tarasenko A. N. Baranov P. B. Glazkov A. V. Kiselev O. V. Ostapenko E. A. Lesina V. S. Baranov 《Russian Journal of Bioorganic Chemistry》2004,30(1):12-20
We attempted to find some compounds for the effective delivery of gene constructs into cells and obtained two trispherical dendrimers on the basis of lysine, (Lys)8-(,-Lys)4-(,-Lys)2-(,-Lys)-Ala-NH2 (D1) and ((Lys)8-(,-Lys)4-(,-Lys)2-,-Lys)-Ala-[Lys(Plm)]2-Ala-NH2 (D2), as well as the starburst polymeric derivatives of D1, (pVIm)
8
-D1 and (pLys)
n
-D1, containing poly(N-vinylimidazole) and polylysine chains single-point bound to the dendrimer amino groups. The conditions of dendrimer–plasmid DNA complex formation were studied. The intracellular localization of these complexes and the expression of gene constructs delivered with their help were analyzed in transfection experiments on the HeLa cell cultures of human epithelial carcinoma and on mouse C2C12 myoblasts. It was found that the chemical structure of dendrimer D1 and its derivatives significantly affected the structure and properties of complex. 相似文献
14.
Magdalena Kanabus Adrianna Nowicka Ewa Sledziewska-Gójska Piotr Jonczyk Zygmunt Ciesla 《Molecular & general genetics : MGG》1995,247(2):216-221
It has previously been suggested that inhibition of the proofreading 3-5 exonuclease activity of DNA polymerase may play an important role in generation of UV-induced mutations inEscherichia coli. Our previous work showing that overproduction of , the proofreading subunit of DNA polymerase III, counteracts the SOS mutagenic response ofE. coli seemed to be consistent with this hypothesis. To explore further the nature of the antimutagenic effect of we constructed plasmid pMK17, which encodes only two of the three highly conserved segments of — Exol and ExoII; the third segment, ExoIII, which is essential for 3–5 exonuclease activity, is deleted. We show that at 40°C, over-production of the truncated e subunit significantly delays production of M13 phage, suggesting that the protein retains its capacity to bind to DNA. On the other hand, the presence of pMK17 in atrpE65 strain growing at 40°C causes a 10-fold decrease in the frequency of UV-induced Trp+ mutations. This antimutagenic effect of the truncated s is effectively relieved by excess UmuD,C proteins. We also show that the presence of plasmid pIP21, which contains thednaQ49 allele encoding an subunit that is defective in proofreading activity, almost completely prevents generation of UV-induced mutations in thetrpE65 strain. We propose that the DNA binding ability of free , rather than its 3–5 exonuclease activity, affects processing of premutagenic UV-induced lesions, possibly by interfering with the interaction between the UmuC-UmuD-RecA complex and Pol III holoenzyme. This interaction is probably a necessary condition for translesion synthesis. 相似文献
15.
This article summarizes some of the evidence for the existence of light-driven structural changes in the and subunits of the chlorplast ATP synthase. Formation of a transmembrane proton gradient results in: (1) a change in the position of the subunit such that it becomes exposed to polyclonal antibodies and to reagents which selectively modifyLys109; (2) enhanced solvent accessibility of several sulfhydryl residues on the subunit; and (3) release/ exchange of tightly bound ADP from the enzyme. These and related experimental observations can, at least partially, be explained in terms of two different bound conformational states of the subunit. Evidence for structural changes in the enzyme which are driven by light or nucleotide binding is discussed with special reference to the popular rotational model for catalysis. 相似文献
16.
A new method is presented for determining the rate of damage to photosynthesis apparatus efficiency caused by stress using the red fluorescence spectra of plant leaves. A direct connection was found between the position of the red fluorescence maximum
max and the photosynthesis apparatus efficiency . The method was tested on several examples and good results were obtained. 相似文献
17.
The association of the human -globin gene with the nuclear matrix was studied in erythroid and non-erythroid cell lines. Using a high salt method to prepare histone depleted nuclei we studied the association of variety of fragments covering a 7.8 kb region which contains the human -globin gene. We furthermore studied the association of a set of DNA fragments covering the 13 kb human G/A-globin gene domain, the 16 kb /-globin gene domain and the 10 kb -globin gene domain with the nuclear matrix of K562 and Raji cells. The results show that all fragments studied are easily released from the nuclear matrix, indicating no specific association.Summarizing our results we could say that a region starting 5.7 kb 5 to the human -globin gene and ending 4 kb 3 to the human -globin gene seems to contain no attachment sites with the nuclear matrix of both erythroid and non-erythroid cells. 相似文献
18.
Kiviharju K Leisola M Eerikäinen T 《Journal of industrial microbiology & biotechnology》2004,31(10):475-481
Streptomyces peucetius var. caesius is an aerobic bacterium that produces doxorubicin as a secondary metabolite. A mixture design was applied for the screening of suitable complex medium components in the cultivation of S. peucetius var. caesius N47, which is an -rhodomycinone-accumulating mutant strain. -Rhodomycinone is a non-glycosylated precursor of doxorubicin. Best growth results were obtained with soy peptone and beef extract. A central composite face-centered (CCF) experimental design was constructed for the investigation of pH, temperature and dissolved oxygen (DO) effects on the cultivation growth phase. Another CCF was applied to the production phase to investigate the effects of aeration, pH, temperature and stirring rate on -rhodomycinone production. An increase in cultivation temperature increased both cell growth and glucose consumption rate. Best -rhodomycinone productivities were obtained in temperatures around 30°C. DO control increased all growth phase responses, but aeration in the production phase coupled with pH decrease resulted in rapid -rhodomycinone decay in the medium. In non-aerated production phases a pH change resulted in better productivity than in experiments without pH change. A pH increase with a temperature decrease seemed most beneficial for productivity. This implies that dynamic control strategies in batch production of -rhodomycinone could increase the overall process productivity. 相似文献
19.
Summary The structure-activity data of 6 years on 395 analogs of the luteinizing hormone releasing hormone (LHRH) have been studied to determine effective substituents for the ten positions for maximal antiovulatory activity and minimal histamine release. The numbers of substituents studied in the ten positions are as follows: (41)1-(12)2-(12)3-(5)4-(47)5-(52)6-(16)7-(18)8-(4)9-(8)10. In position 1, DNal and DQal were effective with the former being more frequently the better substituent. DpClPhe was uniquely effective in position 2. Positions 3 and 4 are very sensitive to change. D3Pal in position 3 and Ser in position 4 of LHRH were in the best antagonists. PicLys and cPzACAla were the most successful residues in position 5 with cPzACAla being the better substituent. Position 6 was the most flexible and many substituents were effective; particularly DPicLys. Leu7 was most often present in the best antagonists. In position 8, Arg was effective for both antiovulatory activity and histamine release; ILys was effective for potency and lesser histamine release. Pro9 of LHRH was retained. DAlaNH2
10 was in the best antagonists.Abbreviations AABLys
N
-(4-acetylaminobenzoyl)lysine
- AALys
N
-anisinoyl-lysine
- AAPhe
3-(4-acetylaminophenyl)lysine
- Abu
2-aminobutyric acid
- ACLys
N
-(6-aminocaproyl)lysine
- ACyh
1-aminocyclohexanecarboxylic acid
- ACyp
1-aminocyclopentanecarboxylic acid
- Aile
alloisoleucine
- AnGlu
4-(4-methoxy-phenylcarbamoyl)-2-aminobutyric acid
- 2ANic
2-aminonicotinic acid
- 6ANic
6-aminonicotinic acid
- APic
6-aminopicolinic acid
- APh
4-aminobenzoic acid
- APhe
4-aminophynylalanine
- APz
3-amino-2-pyrazinecarboxylic acid
- Aze
azetidine-2-carboxylic acid
- Bim
5-benzimidazolecarboxylic acid
- BzLys
N
-benzoyllysine
- Cit
citrulline
- Cl2Phe
3-(3,4-dichlorphenyl)alanine
- cPzACAla
cis-3-(4-pyrazinylcarbonylaminocyclohexyl)alnine
- cPmACAla
cis-3-[4-(4-pyrimidylcarbonyl)aminocyclohexyl]alanine
- Dbf
3-(2-dibenzofuranyl)alanine
- DMGLys
N
-(N,N-dimethylglycyl)lysine
- Dpo
N
-(4,6-dimethyl-2-pyrimidyl)-ornithine
- F2Ala
3,3-difluoroalanine
- hNal
4-(2-naphthyl)-2-aminobutyric acid
- HOBLys
N
-(4-hydroxybenzoyl)lysine
- hpClPhe
4-(4-chlorophenyl)-2-amino-butyric acid
- Hse
homoserine, 2-amino-4-hydroxybutanoic acid
- ICapLys
N
-(6-isopropylaminocaproyl)lysine
- ILys
N
-isopropyllysine
- Ind
indoline-2-carboxylic acid
- INicLys
N
-isonicotinoyllysine
- IOrn
N
-isopropylornithine
- Me3Arg
NG,NG,NG-trimethylarginine
- Me2Lys
N
,N
-dimethyllysine
- MNal
3-[(6-methyl)-2-naphtyl]alanine
- MNicLys
N
-(6-methylpicolinoyl)lysine
- MPicLys
N
-(6-methylpicolinoyl)lysine
- MOB
4-methoxybenzoyl
- MpClPhe
N-methyl-3-(4-chlorphenyl)lysine
- MPZGlu
glutamic acid,-4-methylpiperazine
- Nal
3-(2-naphthyl)alanine
- Nap
2-naphthoic acid
- NicLys
N
-nicotinoyllysine
- NO2B
4-nitrobenzoyl
- NO2Phe
3-(4-nitrophenyl)alanine
- oClPhe
3-(2-chlorphenyl)alanine
- Opt
O-phenyl-tyrosine
- Pal
3-(3-pyridyl)alanine
- 2Pal
3-(2-pyridyl)alanine
- 2PALys
N
-(3-pyridylacetyl)lysine
- pCapLys
N
-(6-picolinoylaminocaproyl)lysine
- pClPhe
3-(4-chlorophenyl)alanine
- pFPhe
3-(4-fluorophenyl)-alanine
- Pic
picolinic acid
- PicLys
N
-picolinoyllysine
- Pip
piperidine-2-car-boxylic acid
- PmcLys
N
-(4-pyrimidylcarbonyl)lysine
- Ptf
3-(4-trifluromethyl phenyl)alanine
- Pz
pyrazinecarboxylic acid
- PzAla
3-pyrazinylalanine
- PzAPhe
3-(4-pyrazinylcarbonylaminophenyl)alanine
- Qal
3-(3-quinolyl)alanine
- Qnd-Lys
N
-quinaldoyllysine
- Qui
3-quinolinecarboxylic acid
- Qux
2-quinoxalinecarboxylic acid
- Tic
1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid
- TinGly
2-thienylglycine
- tNACAla
trans-3-(4-nicotinoylaminocyclohexyl)-alanine
- tPACAla
trans-3-(4-picolinoylaminocyclohexyl)alanine 相似文献
20.
O. E. Voron’ko N. Yu. Yakunina I. A. Strokov I. N. Lavrova V. V. Nosikov 《Molecular Biology》2005,39(2):206-209
A possible association of the polymorphic markers 2/3/4 of the apolipoprotein E gene (APOE) and I /D of the apolipoprotein B gene (APOB) with diabetic polyneuropathy (DPN) was analyzed in patients with type 1 diabetes mellitus (T1DM) with (N=86) or without (N=94) clinical signs of DPN. The two groups did not differ significantly in allele and genotype frequencies of the 2/3/4 polymorphic marker of the APOE gene. Analysis of the allele and genotype frequency distributions of the I/D polymorphic marker of the APOB gene showed that risk of DPN is higher in carriers of allele I or genotype I/I (OR=1.66 and 2.01, respectively) and lower in carriers of allele D (OR=0.60). The results implicate the APOB gene, which codes for one of the major components of the lipid metabolism system, in DPN development in patients with T1DM.__________Translated from Molekulyarnaya Biologiya, Vol. 39, No. 2, 2005, pp. 230–234.Original Russian Text Copyright © 2005 by Voronko, Yakunina, Strokov, Lavrova, Nosikov. 相似文献