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1.
Toshikazu Oki Akihiro Yoshimoto Tatsuo Ogasawara Seiji Sato Akira Takamatsu 《Archives of microbiology》1976,107(2):183-187
The occurrence of adenosine 5-triphosphate-3-diphosphate-synthesizing activity was detected in five strains of actinomycetes; Streptomyces morookaensis, Streptomyces aspergilloides, Streptomyces hachijoensis, Actinomyces violascens and Streptoverticillium septatum, out of 825 strains of actinomycetes, bacteria, fungi and imperfecti. Purine nucleotide pyrophosphotransferase were extracellularly excreted associating with the cell growth, and were purified partially or to apparent homogeniety from the culture filtrate. The enzymes are a monomeric protein with a molecular weight of 18000–26000 and synthesize adenosine, guanosine and inosine 5-phosphate (mono, di or tri)-3-diphosphate such as pApp, ppApp, pppApp, pGpp, ppGpp, pppGpp and pppIpp by transferring a pyrophosphoryl group from the 5-position of ATP, dATP and pppApp to the 3-position of purine nucleotides in the presence of a divalent cation and in alkaline state.Abbreviations pppApp
adenosine 5-triphosphate 3-diphosphate
- ppApp
adenosine 5-diphosphate 3-diphosphate
- pApp
adenosine 5-monophosphate 3-diphosphate
- pppGpp
guanosine 5-triphosphate 3-diphosphate 相似文献
2.
Mr. A. Lees Dr. L. L. Sarliève Dr. N. M. Neskovic Dr. M. Wintzerith P. Mandel 《Neurochemical research》1977,2(1):11-25
Brain composition and developmental changes were investigated in mice homozygous for the locus dwarf, and characterized by a reduced level of growth hormone, thyroid stimulating hormone, and prolactin, and by secondary hypothyroidism. The difference in adult brain weight (–32%) between the dwarf and the normal mice was not found to parallel the difference in body weight (–71%), whereas the differences in the weight of the liver (–79%) and that of the kidney (–75%) did. Several biochemical parameters of brain development were assayed in dwarf and normal mice between the ages of 15 and 210 days. Levels of cerebrosides, sulfatides, gangliosides, phospholipids, cholesterol, protein, and RNA (per gram wet weight) were the same for the dwarf and the controls, but the net difference in total brain DNA was less than the net total brain RNA difference (–11% vs. –27%). Total brain lipids (absolute quantities) were the same at 15 days. The difference was –37% by the 50th day, and remained constant thereafter. No change in the specific activity of 2,3-cyclic nucleotide 3-phosphohydrolase or 3-phosphoadenosine-5-phosphosulfate: galactocerebroside sulfotransferase was observed. These data suggest that the regulation of the development of brain structures is maintained, but the level of the synthesis of the various brain constituents is reduced in proportion to the brain weight. The development of the dwarf brain seems to proceed harmoniously.Abbreviations used PAPS
3-phosphoadenosine-5-phosphosulfate
- PAPS-CST
3-phosphoadenosine-5-phosphosulfate:galactocerebroside sulfotransferase
- CNP
2, 3-cyclic nucleotide 3-phosphohydrolase
- Neu NAc
N-acetylneuraminic acid
This paper is part of the Doctorat d'Etat thesis of L. L. Sarliève. 相似文献
3.
Summary 2-Amino-2-deoxyuridine reacts efficiently with nucleoside 5-phosphorimidazolides in aqueous solution. The dinucleoside monophosphate analogues were obtained in yields exceeding 80% under conditions in which little reaction occurs with the natural nucleosides.In a similar way, the 5-phosphorimidazolide of 2-amino-2-deoxyuridine undergoes self-condensation in aqueous solution to give a complex mixture of oligomers.The phosphoramidate bond in the dinucleoside monophosphate analogues is stable for several days at room temperature and pH 7. The mechanisms of their hydrolysis under acidic and alkaline conditions are described.Abbreviations A
adenosine
- C
cytidine
- G
guanosine
- U
uridine
- T
thymidine
- UN
3
2-azido-2-deoxyuridine
- UNH
2
2-amino-2-deoxyuridine
- ImpA
adenosine 5-phosphorimidazolide
- ImpU
uridine 5-phosphorimidazolide
- ImpUN
3
2-azido-2-deoxyuridine 5-phosphorimidazolide
- ImpUNH
2
2-amino-2-deoxyuridine 5-phosphorimidazolide
- pA
adenosine 5-phosphate
- pU
uridine 5-phosphate
- pUN
3
2-azido-2-deoxyuridine 5-phosphate
- pUNH
2
2-amino-2-deoxyuridine 5-phosphate
- UpA
uridylyl-[35]-adenosine
- UpU
uridylyl-[35]-uridine
- UNpA
adenylyl-[52]-2-amino-2-deoxy-uridine
- UNpU
uridylyl-[52]-2-amino-2-deoxyuridine (pUN)n n=2,3,4 [25]-linked oligomers of pUNH
2 poly(A) polyadenylic acid
- Im
imidazole
- MeIm
l-methylimidazole 相似文献
4.
Summary Short oligocytidylates can act as templates for the self-condensation of guanosine 5-phosphorimidazolide. In the absence of a catalytic metal ion or in the presence of Pb2+ a noticeable template effect is already observed with the dimer and the yield of long oligomers reaches a plateau with a hexamer template. Short templates give oligomers longers than the template length. The products are predominantly 2-5 linked for the Pb2+-catalyzed reaction while mixed linkages are observed in the uncatalyzed reaction.In the presence of Zn2+, a template effect is first observed with the pentamer and is maximal by the heptamer. The products are predominantly 3-5 linked. Oligomers shorter than or as long as the template are obtained in substantial yield, and longer products in much lower yields.Abbreviations G
Guanosine
- Gp
guanosine 2(3)-phosphate
- pG
guanosine 5-phosphate
- Gp!
guanosine cyclic 2,3-phosphate
- ImpG
guanosine 5-phosphorimidazolide
- ImpG*
[8-14C]-guanosine 5-phosphorimidazolide
- pGp
5-phosphoguanosine 2(3)-phosphate
- G2pG
guanylyl-[2-5]-guanosine
- G3pG
guanylyl-[3-5]-guanosine
- ImpGpG
5-phosphorimidazolide of GpG
- (pG)n (n = 2,3)
oligomers of pG
- GppG
P1, P2-diguanosine 5-diphosphate
- GppGpG
5-[guanosine 5-pyrophosphate] of GpG
- NH2pG
guanosine 5-phosphoramidate
- (pG)4+
tetramer and higher oligoguanylates with 5 terminal phosphate
- oligo(G)
oligoguanylate
- Cp
cytidine 2(3)-phosphate
- Cp!
cytidine cyclic 2,3-phosphate
- (Cp)n–1 Cp! (n= 2,3,4)
oligocytidylates terminated by 5-OH groups and 2,3-cyclic phosphates
- oligo(C)
oligocytidylate
- poly(C)
polycytidylic acid
- poly(U)
polyuridylic acid
- poly(C,G)
random copolymer of C and G
- BAP
bacterial alkaline phosphatase (E. coli)
- EDTA
ethylenediaminetetraacetic acid
- Rf
chromatographic mobility 相似文献
5.
Roots of spinach (Spinacia oleracea L.) seedlings contained only a very low activity of adenosine 5-phosphosulfate sulfotransferase compared to the cotyledons. Adenosine 5-phosphosulfate sulfotransferase activity increased about tenfold in cotyledons during greening. Preparation of organelle fractions from spinach leaves by a combination of differential and isopycnic density gradient centrifugation showed that adenosine 5-phosphosulfate sulfotransferase banded with NADP-glyceraldehyde-3-phosphate dehydrogenase, a marker enzyme for intact chloroplasts. In the fractions of peroxisomes, mitochondria and broken chloroplasts virtually no adenosine 5-phosphosulfate sulfotransferase activity was measured. Comparison with the chloroplast enzyme NADP-glyceraldehyde-3-phosphate dehydrogenase indicates that in spinach, adenosine 5-phosphosulfate sulfotransferase is localized almost exclusively in the chloroplasts.Abbreviations APS
Adenosine 5-phosphosulfate
- APSSTase
Adenosine 5-phosphosulfate sulfotransferase
- BSA
Bovine serum albumin
- BRIJ58
Polyethylene glycolmonostearylether
- DTE
Dithioerythritol
- DTT
Dithiothreitol
- EDTA
Ethylenediaminetetraacetic acid
- ME
2-Mercaptoethanol
- NADP-GPD
NADP-linked glyceraldehyde-3-phosphate dehydrogenase
- PAPS
Adenosine 3-phosphate 5-phosphate 5-phosphosulfate
- POPOP
1,4 Di [2-(5-phenyloxazolyl)]-benzene
- PPO
2,5-Diphenyloxazol
The results presented in this paper are taken from the Ph. D. thesis of H.F. 相似文献
6.
Purified ribulose-bisphosphate carboxylase (EC 4.1.1.39) was strongly and equally inhibited either by ADP or GDP and to a lesser extent by IDP. AMP or ATP exerted little effect on activity. Inhibition by the nucleotide diphosphates was competitive with respect to RuBP and non-competitive with respect to CO2 and Mg2+, respectively. Treatment of the enzyme with urea or guanidine-HCl resulted in rapid loss of activity that was not restored by dialysis even in the presence of Mg2+ and cysteine. Sodium dodecyl sulfate electrophoresis of 8.0 M urea treated enzyme revealed the presence of a fast-moving (small) sub-unit with molecular weight 14150 and a slower moving (large) sub-unit with molecular weight 68000. Examination of native enzyme by sodium dodecyl sulfate electrophoresis gave sub-units of 13700 and 55500 respectively. The amino acid content standardized to phenylalanine was essentially similar to that from other sources. Arrhenius plots showed a break at 29°C with an E
a of 12.34 kcal per mole for the steeper part of the curve and a H of 11.43 kcal per mole while for the less steep region, the E
a was 1.04 kcal per mole and the H 1.92 kcal per mole.Abbreviations ADP
adenosine-5-diphosphate
- AMP
adenosine-5-monophosphate
- ATP
adenosine-5-triphosphate
- CDP
cytidine-5-diphosphate
- CMP
cytidine-5-monophosphate
- CTP
cytidine-5-triphosphate
- FDP
fructose-1,6-diphosphate
- F6P
fructose-6-phosphate
- GDP
guanosine-5-diphosphate
- GMP
guanosine-5-monophosphate
- G6P
glucose-6-phosphate
- GTP
guanosine-5-triphosphate
- IDP
inosine-5-diphosphate
- IMP
inosine-5-monophosphate
- PEP
phosphoenolpyruvate
- 6PG
6-phosphogluconate
- R1P
ribose-1-phosphate
- R5P
ribose-5-phosphate
- RuBP
ribulose-1,5-bisphosphate
- SDS
sodium dodecyl sulfate
- TDP
thymidine-5-diphosphate
- TMP
thymidine-5-monophosphate
- TTP
thymidine-5-triphosphate
- UDP
uridine-5-diphosphate
- UMP
uridine-5-monophosphate
- UTP
uridine-5-triphosphate 相似文献
7.
Summary Organic pyrophosphates such as UppA and NAD are formed when a solution containing a nucleotide, a nucleoside 5-polyphosphate, Mg2+ and imidazole are allowed to dry out. We suggest that this synthesis may have occured concurrently with oligonucleotide formation.Abbreviations Im
Imidazole
- CDI
1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride
- EDTA
ethylenediaminetetraacetic acid
- A
adenosine
- U
uridine
- pnA
adenosine 5-poly-phosphate containing n phosphate residues
- pU
uridine 5-phosphate
- AppA
P1,P2-diadenosine 5-pyrophosphate
- UppA
P1-(uridine 5)-P2-(adenosine 5)-pyrophosphate
- ImpA
adenosine 5-phosphorimidazolide
- NMN
nicotinamide mononucleotide
- NAD
nicotinamide-adenine dinucleotide 相似文献
8.
Arthur L. Weber 《Journal of molecular evolution》1987,25(1):7-11
Summary Reaction ofDl-serine and adenosine-5-phosphorimidazolide in the presence of adenosine-5-(O-methylphosphate) and imidazole resulted in the stereoselective synthesis of the aminoacyl nucleotide ester 2(3)-O-seryl-adenosine-5-(O-methylphosphate). The enantiomeric excess ofd-serine incorporated into 2(3)-O-seryl-adenosine-5-(O-methylphosphate) was about 9%. Adenylyl-(5N)-serine and an unknown product also incorporated an excess ofd-serine; however, serylserine showed an excess ofl-serine. The relationship of these results to the origin of the biological pairing ofl-amino acids and nucleotides containingd-ribose is discussed. 相似文献
9.
When tested in a poly(U)-dependent polyphenylalanine synthesizing system and in a postnuclear supernatant, both derived from Ehrlich ascites tumor cells, 2(3),5-ADP did not affect chain elongation of polypeptide synthesis. In a cell-free system which was dependent on initiation and programmed by natural mRNA, however, the amino acid incorporating activity was suppressed to about 10% of the control in the presence of 1 mM 2(3),5-ADP. The inhibitor was shown not to interfere with the attachment of poly(U) to the small ribosomal subunit and with the formation of mRNA-80S ribosome complexes in a complete protein synthesizing system. The subsequent attachment of a 40S ribosomal subunit to the mRNA-80S ribosome complex and the formation of polysomes, however, was depressed by the inhibitor. The experimental results suggest that 2(3),5-ADP inhibits initiation-dependent protein synthesis between monosome formation and the formation of the first peptide bond(s). 相似文献
10.
Ahlert Schmidt 《Archives of microbiology》1977,112(3):263-270
Crude extracts of Rhodospirillum rubrum catalyzed the formation of acid-volatile radioactivity from (35S) sulfate, (35S) adenosine-5-phosphosulfate, and (35S) 3-phosphoadenosine-5-phosphosulfate. An enzyme fraction similar to APS-sulfotransferases from plant sources was purified 228-fold from Rhodospirillum rubrum. It is suggested here that this enzyme is specific for adenosine-5-phosphosulfate, because the purified enzyme fraction metabolized adenosine-5-phosphosulfate, however, only at a rate of 1/10 of that with adenosine-5-phosphosulfate. Further, the reaction with 3-phosphoadenosine-5-phosphosulfate was inhibited with 3-phosphoadenosine-5-phosphate whereas this nucleotide had no effect on the reaction with adenosine-5-phosphosulfate. For this activity with adenosine-5-phosphosulfate the name APS-sulfotransferase is suggested. This APS-sulfotransferase needs thiols for activity; good rates were obtained with either dithioerythritol or reduced glutathione; other thiols like cysteine, 2-3-dimercaptopropanol or mercaptoethanol are less effective. The electron donor methylviologen did not catalyze this reaction. The pH-optimum was about 9.0; the apparent K
m for adenosine-5-phosphosulfate was determined to be 0.05 mM with this so far purified enzyme fraction. Enzyme activity was increased with K2SO4 and Na2SO4 and was inhibited by 5-AMP. These properties are similar to assimilatory APS-sulfotransferases from spinach and Chlorella.Abbreviations APS
adenosine-5-phosphosulfate
- PAPS
3-phosphoadenosine-5-phosphosulfate
- 5-AMP
adenosine-5-monophosphate
- 3-AMP
adenosine-3-monophosphate
- 3-5-ADP
3-phosphoadenosine-5-phosphate (PAP)
- DTE
dithiorythritol
- GSH
reduced glutathione
- BAL
2-3-dimercaptopropanol 相似文献
11.
The sedentary fauna of sublittoral boulders was studied at five sites with very different environmental conditions within Lough Hyne Marine Nature Reserve (51° 30 N, 9° 18 W). The degree of competition was assessed through the construction of competitive hierarchies built up from the results of nearly 3000 interactions between organisms. Communities at all sites were predominantly hierarchically organised with few stand-offs recorded. Density of interactions was correlated with total space occupation. Flow speed at all sites was logged over 24 h and this factor also correlated with space occupation. Degree of disturbance was assessed through the use of marked boulders at each site. Species diversity peaked where all factors were moderate and was lowest at extreme sites. The effects of these environmental variables and biotic factors in determining community composition are discussed, and a working model detailing a Minimum Stress Inflexion is described. This represents an extension of the intermediate disturbance hypothesis in that it is proposed that disturbance in this system may serve to reduce sediment load as opposed to preventing space monopolisation in the classical model. 相似文献
12.
Cytochemical studies on the localization of 5′-nucleotidase in the acinar cells of the rat salivary glands 总被引:1,自引:0,他引:1
Summary The cytochemical localization of 5-nucleotidase (5-AMPase), and its validity, were investigated in parotid and submandibular acinar cells of a rat. Biochemical determinations showed that adequate treatment with glutaraldehyde could minimize the loss of enzymatic activity, and that 5-AMPase and non-specific alkaline phosphatase (-GPase) possessed different pH optima.The cytochemical distribution of the reaction products from the 5-AMPase activity was distinct from those of -GPase. 5-AMPase activity was localized on the surface membranes of acinar, ductal and myoepithelial cells of both salivary glands. -GPase activity was evenly distributed on the entire plasma membranes of myoepithelial cells and on the basal plasmalemma of acinar cells. The reaction products, which appeared on the luminal and lateral plasma membranes of the acinar cells, were presumed to reflect the presence of 5-AMPase, while those on the myoepithelial surface and basal plasma membranes of the acinar cells demonstrated both 5-AMPase and -GPase.The results indicate that 5-AMPase activity can be utilized as a reliable marker enzyme of plasma membranes in the salivary acinar cells. 相似文献
13.
Summary Soluble lead salts and a number of lead-containing minerals catalyze the formation of oligonucleotides from nucleoside 5-phosphorimidazolides. The effectiveness of lead compounds correlates strongly with their solubility. Under optimal conditions we were able to obtain 18% of pentamer and higher oligomers from ImpA. Reactions involving ImpU gave smaller yields.Abbreviations A
adenosine
-
U
uridine
-
Im
imidazole
-
MeIm
1-methyl-imidazole
-
EDTA
ethylenediaminetetraacetic acid
-
pA
adenosine 5-phosphate
-
pU
uridine 5-phosphate
-
Ap
adenosine cyclic 2:3-phosphate
-
ATP
adenosine 5-triphosphate
-
AppA
P1,P2-diadenosine 5-diphosphate
-
pNp (N = A,U)
nucleotide 2(3), 5-diphosphate
-
ImpA
adenosine 5-phosphoreimidazolide
-
ImpU
uridine 5-phosphorimidazolide
-
A
2pA
adenylyl-[25]-adenosine
-
A
3pA
adenylyl-[35]-adenosine
-
pA
2pA
5-phospho-adenylyl-[25]-adenosine
-
pA
3pA
5-phospho-adenylyl-[35]-adenosine
-
pUpU
5-phospho-uridylyl-uridine
-
pApU
5-phospho-adenylyl-uridine
-
pUpA
5-phospho-uridylyladenine
-
(pA)n (n, 2,3,4,)
oligoadenylates with 5 terminal phosphate
-
ImpApA
5-phosphorimidazolide of adenylyl adenosine
-
(pA)
5+
pentamer and higher oligoadenylates with 5 terminal phosphate
-
(Ap)nA (n = 2,3,4)
oligoadenylates without terminal phosphates
In the following we do not specify the nature of the internucleotide linkageIn the following we do not specify the nature of the internucleotide linkage 相似文献
14.
The origin of Q-independent derivatives of phage lambda 总被引:13,自引:0,他引:13
Kim Kaiser 《Molecular & general genetics : MGG》1980,179(3):547-554
Summary qsr (Q-independent) phages are characterised by the replacement of the region of the genome that contains Q, S, R, and the late gene promoter, PR, with host-derived DNA that codes for functions analogous to those deleted. Restriction endonuclease analysis and DNA/DNA hybridisation methods have been used to show that p4 and qin A 3, two such Q-independent phages, are the product of recombination between and a defective lambdoid prophage (the qsr prophage) located at an as yet unidentified site in the E. coli K 12 chromosome. The qsr prophage is distinct from the defective lambdoid prophage Rac (Kaiser and Murray 1979). In the E. coli K 12 strain AB1157 from which qsr phages cannot be generated, the qsr prophage has suffered an internal deletion. That the qsr prophage appears not to carry a full complement of essential late genes suggests one explanation for its apparently defective nature. 相似文献
15.
Suzuki Hisanori Buonamassa Daniela Tornese Weisz Alessandro 《Molecular and cellular biochemistry》1990,99(1):33-39
Summary The activity of poly (ADP-ribose) polymerase (ADPRP) and the content of 2,5-oligodenylates core (2,5An; n = 2,3 and 4) were measured in homogenates of the uterus and of the liver of immature rats immediately before (time 0) or at different times after injection of estradiol-valerate. ADPRP activity increased gradualy, starting 6 hours after estrogen injection, for about 4 days. Instead, the content of 2,5 An decreased by about 50% within 6 hours, and thereafter more slowly for 4 days to about 20% of starting values. Estrogen increased ADPRP activity and decreased 2,5An concentration also in the kidney and in the cardiac muscle of the same animals, but not in the skeletal muscle, where neither of the two parameters was affected. Injection of vehicle only (sesame oil) had no effect on ADPRP activity nor on 2,5An content of immature rat tissues. 相似文献
16.
V. V. Kotusov M. K. Kukhanova A. A. Krayevsky B. P. Gottikh 《Molecular biology reports》1976,3(2):151-156
50 S subunits of E. coli ribosomes catalyze the reaction of the 2(3)-N-(formyl) methionine ester of adenosine 5-phosphate and Phe-tRNA resulting in peptide bond synthesis. Cytidine 5-phosphate stimulates this process on 50 S ribosomal subunits as well as on intact ribosomes. The obtained data show that the areas of the peptidyltransferase donor site which binds the 3-terminal fragment of peptidyl-tRNA possess completely formed structures on 50 S ribosomal subunits. 相似文献
17.
Purified myelin from fresh calf brain white matter was subfractionated in a discontinuous sucrose gradient; significant recovery of protein and 2,3-cyclic nucleotide 3-phosphohydrolase (CNP) and 5-nucleotidase (5N) activities occurred in all three obtained subfractions, the highest recovery being in the light subfraction; highest 5N and CNP specific activities were in medium myelin. Purified myelin was also subfractionated in a continuous sucrose gradient, with a similar localization of protein; CNP activity and 5N activity maxima suggest that myelin may be a predominant locus of 5N in bovine brain white matter. Freezing of brain white matter caused an increase in protein and in CNP and 5N total activity recoveries in denser myelin subfractions. Cytochemistry showed the reaction product of 5N in the whole myelin fraction to be associated with the innermost, outermost and medial compact myelin layers. Effects of non-ionic detergent (Lubrol WX) on 5N activity were studied, and the results also suggest the intrinsic nature of 5N as an ectoenzyme in myelin membranes. Lubrol WX was viewed as an advisable detergent for the stimulation of myelin 5N activity, but not for the solubilization of this enzyme. 相似文献
18.
J. P. Ferris H. Yanagawa W. J. Hagan Jr. 《Origins of life and evolution of the biosphere》1984,14(1-4):99-106
Diiminosuccinonitrile (DISN), formed by the oxidation of diaminomaleonitrile (DAMN), has been investigated as a potential prebiotic phosphorylating agent. DISN effects the cyclization of 3-adenosine monophosphate to adenosine 2, 3-cyclic phosphate in up to 39% yield. The mechanism of this reaction was investigated. The DISN-mediated phosphorylation of uridine to uridine monophosphate does not proceed efficiently in aqueous solution. The reaction of DISN with uridine-5-phosphate and uridine results in the formation of 2,2-anhydronucleotides and 2,2-anhydronucleosides respectively, and other reaction products resulting from an initial reaction at the 2- and 3-hydroxyl groups. The clay mineral catalysis of the cyclization of adenosine-3-phosphate was investigated using homoionic montmorillonites. 相似文献
19.
Rabbit anti-mouse-Ia serum was raised against Ia specificities present in CBAJH (H-2
k) serum. This xenogeneic antiserum was considered to react with similar specificities to those detected by mouse anti-Iak alloantisera and more evidence is now presented for this contention. By absorption, the xenogeneic antiserum was found to react with spleen, lymph node, bone marrow, and thymus, reactions similar to that found with the allogeneic anti-Iak antiserum. Furthermore, red cells, platelets, brain, kidney, and liver could not absorb the activity from the xenogeneic antiserum, demonstrating the selective tissue distribution of the antigens reactive with this serum. This reactive population was previously shown to consist of B cells and a subpopulation of T cells. In a backcross study of (C57BL/6 × A)F1 × C57BL/6, the rabbit anti-Ia and mouse anti-Ia reactions were found to segregate together, and some evidence for the genetic regulation of the expression of Ia specificities was also found. By direct testing, and by absorption testing using a number of strains, the xenogeneic antiserum was shown to contain high titers of antibody to Ia.1, 3, 7, 15, and 17; lower titers to Ia.19, and 22; little antibody to Ia.18, and no reaction for the private specificity Ia. 2, although the multiple absorptions required to define these specificities may have observed some reactions. The data indicate that the xenogeneic and allogeneic anti-Iak antisera recognize similar Ia determinants, which map to theLA, IE andIC subregions of theH-2 complex. These have been given the same specificity designation as the allogeneic specificities, but they are separately identified by a prime ('). 相似文献
20.
Summary Evaporation of a solution of thymidine plus either theexo or theendo diastereomer of uridine cyclic 2,3-O, O-phosphorothioate (U > p(S) in 1,2-diaminoethane hydrochloride buffer gave the 2,5 and 3,5 isomers of (P-thio) uridylylthymidine (Up(S)dT) in a ratio of 1:2 with a combined yield of about 20%. These isomers were re-converted to U > p(S) and dT by a reaction that is known to proceed by an in-line mechanism. Both the 2,5 and 3,5 isomers gave as product the same diastereomer of U > p(S) that had been used originally in their formation. These dry-state prebiotic reactions (Verlander, Lohrmann, and Orgel 1973) are thus shown to be stereospecific, and both the 2,5 and 3,5 internucleotide bonds are formed by an in-line mechanism.Abbreviations DAE
1,2-diaminoethane
- HPLC
high pressure liquid chromatography
- RNase
bovine pancreatic ribonuclease A, EC 3.1.4.22
- TEAB
triethylammonium bicarbonate
- tris
tris(hydroxymethyl)aminomethane
- UMP(S)
uridine monophosphorothioate
- U > p
uridine cyclic 2,3-phosphate
- U > p(S)
uridine cyclic 2,3-O, O-phosphorothioate
- Up(S)dT
(P-thio)uridylylthymidine
- U2p(Rp-S)5dT
(P-thio)uridylylthymidine with theR configuration at phosphorous, and a 2,5 internucleotide linkage 相似文献