scholarly journals Chemical taxonomy of the hinge-ligament proteins of bivalves according to their amino acid compositions

1987 ◽  
Vol 242 (2) ◽  
pp. 505-510 ◽  
Author(s):  
Y Kikuchi ◽  
N Tamiya
Keyword(s):  
Amino Acid ◽  
Phylogenetic Relationship ◽  
Pearl Oyster ◽  
The Other ◽  
Amino Acid Compositions ◽  
New Class ◽  
Oyster Species ◽  
Other Hand ◽  
Good Agreement

The proteins in the hinge ligaments of molluscan bivalves were subjected to chemotaxonomic studies according to their amino acid compositions. The hinge-ligament protein is a new class of structure proteins, and this is the first attempt to introduce chemical taxonomy into the systematics of bivalves. The hinge-ligament proteins from morphologically close species, namely mactra (superfamily Mactracea) or scallop (family Pectinidae) species, showed high intraspecific homology in their compositions. On the other hand, inconsistent results were obtained with two types of ligament proteins in pearl oyster species (genus Pinctada). The results of our chemotaxonomic analyses were sometimes in good agreement with the morphological classifications and sometimes inconsistent, implying a complicated phylogenetic relationship among the species.

Oxytocin analogues with non-coded amino acid residues in position 8: [8-Neopentylglycine]oxytocin and [8-cycloleucine]oxytocin

1987 ◽  
Vol 52 (9) ◽  
pp. 2317-2325 ◽  
Author(s):  
Jan Hlaváček ◽  
Jan Pospíšek ◽  
Jiřina Slaninová ◽  
Walter Y. Chan ◽  
Victor J. Hruby
Keyword(s):  
Amino Acid ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
The Other ◽  
Amino Acid Residues ◽  
Phase Synthesis ◽  
Other Hand ◽  
Fragment Condensation

[8-Neopentylglycine]oxytocin (II) and [8-cycloleucine]oxytocin (III) were prepared by a combination of solid-phase synthesis and fragment condensation. Both analogues exhibited decreased uterotonic potency in vitro, each being about 15-30% that of oxytocin. Analogue II also displayed similarly decreased uterotonic potency in vivo and galactogogic potency. On the other hand, analogue III exhibited almost the same potency as oxytocin in the uterotonic assay in vivo and in the galactogogic assay.

Comparison of the Potency of 8-L-Arginine, 8-D-Arginine and 8-D-Homoarginine Vasopressin Analogs with Substituted Phenylalanine in Position 2

1994 ◽  
Vol 59 (6) ◽  
pp. 1439-1450 ◽  
Author(s):  
Miroslava Žertová ◽  
Jiřina Slaninová ◽  
Zdenko Procházka
Keyword(s):  
Amino Acid ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Basic Amino Acid ◽  
The Other ◽  
Side Chain ◽  
Inhibitory Potency ◽  
Phase Synthesis ◽  
Other Hand ◽  
Order Of Magnitude

An analysis of the uterotonic potencies of all analogs having substituted L- or D-tyrosine or -phenylalanine in position 2 and L-arginine, D-arginine or D-homoarginine in position 8 was made. The series of analogs already published was completed by the solid phase synthesis of ten new analogs having L- or D-Phe, L- or D-Phe(2-Et), L- or D-Phe(2,4,6-triMe) or D-Tyr(Me) in position 2 and either L- or D-arginine in position 8. All newly synthesized analogs were found to be uterotonic inhibitors. Deamination increases both the agonistic and antagonistic potency. In the case of phenylalanine analogs the change of configuration from L to D in position 2 enhances the uterotonic inhibition for more than 1 order of magnitude. The L to D change in position 8 enhances the inhibitory potency negligibly. Prolongation of the side chain of the D-basic amino acid in position 8 seems to decrease slightly the inhibitory potency if there is L-substituted amino acid in position 2. On the other hand there is a tendency to the increase of the inhibitory potency if there is D-substituted amino acid in position 2.

scholarly journals Holographic RG flows and Janus solutions from matter-coupled $$N=4$$ gauged supergravity

2021 ◽  
Vol 81 (6) ◽  
Author(s):  
Parinya Karndumri
Keyword(s):  
Gauge Group ◽  
The Other ◽  
Three Dimensions ◽  
New Class ◽  
Other Hand ◽  
Genuine Solution ◽  
Coupled Theory

AbstractWe study an $$SO(2)\times SO(2)\times SO(2)\times SO(2)$$ S O ( 2 ) × S O ( 2 ) × S O ( 2 ) × S O ( 2 ) truncation of four-dimensional $$N=4$$ N = 4 gauged supergravity coupled to six vector multiplets with $$SO(4)\times SO(4)$$ S O ( 4 ) × S O ( 4 ) gauge group and find a new class of holographic RG flows and supersymmetric Janus solutions. In this truncation, there is a unique $$N=4$$ N = 4 supersymmetric $$AdS_4$$ A d S 4 vacuum dual to an $$N=4$$ N = 4 SCFT in three dimensions. In the presence of the axion, the RG flows generally preserve $$N=2$$ N = 2 supersymmetry while the supersymmetry is enhanced to $$N=4$$ N = 4 for vanishing axion. We find solutions interpolating between the $$AdS_4$$ A d S 4 vacuum and singular geometries with different residual symmetries. We also show that all the singularities are physically acceptable within the framework of four-dimensional gauged supergravity. Accordingly, the solutions are holographically dual to RG flows from the $$N=4$$ N = 4 SCFT to a number of non-conformal phases in the IR. We also find $$N=4$$ N = 4 and $$N=2$$ N = 2 Janus solutions with $$SO(4)\times SO(4)$$ S O ( 4 ) × S O ( 4 ) and $$SO(2)\times SO(2)\times SO(3)\times SO(2)$$ S O ( 2 ) × S O ( 2 ) × S O ( 3 ) × S O ( 2 ) symmetries, respectively. The former is obtained from a truncation of all scalars from vector multiplets and can be regarded as a solution of pure $$N=4$$ N = 4 gauged supergravity. On the other hand, the latter is a genuine solution of the full matter-coupled theory. These solutions describe conformal interfaces in the $$N=4$$ N = 4 SCFT with $$N=(4,0)$$ N = ( 4 , 0 ) and $$N=(2,0)$$ N = ( 2 , 0 ) supersymmetries.

Polysomal organization in growing and resting cultures and its relation to protein synthesis in Tetrahymena

1983 ◽  
Vol 59 (1) ◽  
pp. 121-131
Author(s):  
P. Isberner ◽  
G. Cleffmann
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Growth Conditions ◽  
The Other ◽  
Protein Accumulation ◽  
Resting Cells ◽  
Amino Acid Incorporation ◽  
Total Rna ◽  
Acid Incorporation ◽  
Other Hand

Cytosol from Tetrahymena cells growing at different rates was isolated and separated by centrifugation into polysomal and non-polysomal fractions. The RNAs of either fraction were separated chromatographically into poly(A)+ RNA and poly(A)-RNA. It was found that in resting cultures the total RNA per cell is only about half of that of rapidly growing cultures. All fractions of RNA were reduced proportionally. Thus, the percentage of polysomally bound total RNA (70% of cytosol RNA) and polysomally bound poly(A)+ RNA (72% of cytosol poly(A)+ RNA) is the same in growing and resting cultures. Differences, however, were found in the polysomal structure. Polysomes from resting cultures contained significantly fewer ribosomes. The amounts of RNA bound to polysomes were related to the rate of protein synthesis under different growth conditions. The decrease in cellular RNA corresponded well with the reduction in amino acid incorporation in resting cells. The rate of protein accumulation in resting cells, on the other hand, was considerably less, suggesting that polypeptides in resting cultures are less stable.

Radioprotective and Radiosensitizing Effects of Sulfur-Containing Amino Acid Derivatives on Mice

1980 ◽  
Vol 35 (9-10) ◽  
pp. 726-728 ◽  
Author(s):  
Akihisa Nishimura ◽  
Michinobu Hashimoto ◽  
Katsunobu Konno ◽  
Yasuhiko Ohta ◽  
Satoshi Tahara ◽  
...  
Keyword(s):  
Body Weight ◽  
Amino Acid ◽  
Radioprotective Effect ◽  
The Other ◽  
Amino Acid Derivatives ◽  
Survival Ratio ◽  
Other Hand ◽  
Hydantoin Derivatives ◽  
Γ Rays ◽  
Sulfur Containing

Both protection and sensitization of Mice C57BL against 60Co γ-rays by sulfur-containing amino acid derivatives - S-alkyl-L-cysteines, S-alkyl-2-methyl-DL-cysteines and their hydantoin derivatives, and sulfoxides of these compounds - were examined. DL-5-Allylthiomethyl-5-methylhydantoin (150 mg/kg body weight) had a remarkable radioprotective effect. The survival ratio was 4.33 or above two times as much as that of L-cysteine. On the other hand, its sulfoxide had a radiosensitizing effects; survival ratio, 0.333.

scholarly journals Effect of inhibition of DNA synthesis on mating inEscherichia coliK12

1965 ◽  
Vol 6 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Susan Hollom ◽  
R. H. Pritchard
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Amino Acid Starvation ◽  
The Other ◽  
Thymine Starvation ◽  
Other Hand ◽  
Inhibition Of Dna Synthesis ◽  
Polynucleotide Chain

From studies involving inhibition of DNA synthesis in Hfr strains ofEscherichia coliK12, either by thymine starvation (Pritchard, 1963) or amino-acid starvation (Suit, Matney, Doudney & Billen, 1964), during mating withF−strains, it has been concluded that transfer of DNA from males to females can occur in the absence of DNA synthesis. This conclusion is at variance with the hypothesis (Jacob, Brenner & Cuzin, 1963) that the energy required for transfer is derived from the process of DNA replication. On the other hand, a second prediction from this hypothesis, that one polynucleotide chain of the DNA transferred during mating will have been synthesized during transfer, is strongly supported by recent experiments (Ptashne, 1965; Blinkova, Bresler & Lanzov, 1965; Gross & Caro, 1965).

scholarly journals Characterization of Missense Mutations in Factor VIII That Lead to Abnormal N-Linked Glycosylation

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3764-3764 ◽  
Author(s):  
Wei Wei ◽  
Xiaofan Zhu ◽  
Renchi Yang ◽  
Bin Zhang
Keyword(s):  
Amino Acid ◽  
Factor Viii ◽  
Amino Acid Substitution ◽  
Hemophilia A ◽  
Consensus Sequence ◽  
The Other ◽  
Missense Mutations ◽  
Other Hand ◽  
Glycosylation Sites ◽  
A2 Domain

Abstract Most secreted proteins are glycosylated on the asparagine (N) residue with the consensus sequence N-X-S/T(X≠Proline).Coagulation factor VIII (FVIII) is heavily N-linked glycosylated with 5 consensus sites outside the B domain. However, the roles of these glycans are not well understood. Meanwhile, missense mutations which could create additional N-linked glycosylation sites have largely not been characterized in hemophilia A patients. In this study we first expressed individual domains of FVIII and determined that the A2, Cand C2 domains are efficiently secreted. The A1(N42,N239), A3 (N1810)and C1 (N2118)domains are glycosylated, whereas N582 in the A2 domain is not glycosylated. Only one hemophilia A missense mutation, S241C in the A1 domain, was found to abolish the consensus sequence for N-linked glycosylation at N239. We confirmed that the S241C mutant lost one glycan and became unstable inside cells. We also tested the other three glycosylation sites and found that elimination of the N-linked glycan at N2118 (N2118Q mutation) impaired the secretion of the C domain. This defect could not be rescued by adding another N-linked glycan (at N2062) in the C1 domain, indicating that the N2118 glycan is specifically required for the secretion of the C domain. We next searched the CHAMP F8 Mutation Database and the FVIII Variant Database and identified 19 missense mutations that potentially create an ectopic glycosylation site.These mutations are located in A1, A2, A3 and C1 domains, but none in the C2 domain. Only two mutations (I566T and M1772T) have previously been characterized.We found that all but one (I2071T) of these mutations gained an additional N-linked glycan. We further studied missense mutations in the A2 (A469T, A469S, I566T, M614T and G701S) and the C domain (W2062S, I2071T and D2131N) because these domains are secreted in cell culture. Whereas secretion of I566T, W2062S and D2131N mutants was comparable to their wild-type counterparts, secretion of other mutants decreased to 5%-30% of WT (P<0.05). Mutants that secreted into culture media nevertheless have low FVIII activity (<2%), indicating that these mutations cause cross reactive material positive hemophilia A. The consequences of additional N-linked glycan were further investigated using the A2 domain mutants, since this domain is normally unglycosylated. After treating with tunicamycin to block the N-linked glycosylation process in the endoplasmic reticulum (ER),the secretion of A2 domain with I566T andG701Smutants, which had relatively high secretion levels, decreased significantly. On the other hand, removing the additional glycan boosted the secretion of A469S and A469T, two low-secretion mutants.Tunicamycin treatment had no effect on another low secretion mutant,M614T.These results suggest that amino acid substitution in I566T andG701Smutationsis detrimental to the proper folding of the protein and the additional N-glycan plays a stabilization role. On the other hand, additional N-glycan plays a destabilization role in A469S and A469T mutations, contributing to disruption of folding in these mutants. For theM614Tmutation,the amino acid substitution alone is likely sufficient todestroy the protein folding. We also studied interactions of abnormally glycosylated mutants with ER chaperones.All the mutants with low secretion levels significantly induced expression of GRP78 to 1.5-2.0 folds(P<0.05), while mutants that maintain higher secretion levels did not affect GRP78 expression. The low secretion mutants also had increased binding to GRP78 and calreticulin, but not to calnexin.Therefore ER chaperones play a key role in the ER quality control of FVIII mutants. In conclusion, our results indicate that the effects of abnormal N-linked glycosylation on FVIII folding and secretionvary widely, from detrimental to beneficial. The impact of a particular glycan is likely determined by the location and the underlying amino acid change caused by the mutation. Disclosures No relevant conflicts of interest to declare.

The Separation of Light Gaseous Isotopes by Mass Diffusion Columns II

1964 ◽  
Vol 19 (6) ◽  
pp. 747-755
Author(s):  
W. J. De Wet ◽  
J. Los
Keyword(s):  
Theoretical Analysis ◽  
Mass Diffusion ◽  
Experimental Results ◽  
The Other ◽  
Countercurrent Flow ◽  
Gas Solubility ◽  
Flow Rates ◽  
Mixing Effects ◽  
Other Hand ◽  
Good Agreement

The design of mass diffusion columns operated with partition membranes, for the separation of light gaseous isotopes, is discussed. A theoretical analysis of experimental results obtained indicates that a good agreement between experimental results and theory is only obtained at low column pressures and moderate countercurrent flow rates. At fairly low countercurrent flow rates mixing effects due to viscous dragging and gas solubility by the condensate appear to be considerable whereas excessively high countercurrent flow rates, on the other hand, also seem undesirable. Some suggestions are proposed to obviate impairing effects at least to some extent.

scholarly journals The Chemotherapy of Infectious Diseases Caused by Protozoa and Bacteria

1936 ◽  
Vol 29 (4) ◽  
pp. 313-324 ◽  
Author(s):  
H. Hörlein
Keyword(s):  
Infectious Diseases ◽  
Bacterial Infections ◽  
The Other ◽  
Virus Diseases ◽  
Pathogenic Organism ◽  
New Class ◽  
Other Hand ◽  
Synthetic Drug ◽  
Micro Organisms ◽  
Active Substances

The possibility of combating infectious diseases with chemotherapeutically active substances depends to a large extent on the structure of the pathogenic organism. Apart from the cure of contagious pleuro-pneumonia in horses with neosalvarsan, we have, as yet, no chemotherapeutic substance which is active in virus diseases. The position is scarcely better when we turn to bacterial infections due to cocci and bacilli. These two types of infective organisms occupy the lowest level in the scale of micro-organisms. On the other hand, the spirochætes, which also belong to the bacteria group, and, still more so, those causal organisms belonging to the protozoa, represent relatively highly differentiated species, and the more highly developed a pathogenic organism is, the more points for attack it appears to offer to the action of chemotherapeutic substances. It is, therefore, not to be wondered at that the best results with chemotherapeutically active substances have been obtained in spirochætal diseases (syphilis, relapsing fever, frambœsia, etc.), and above all, in protozoal diseases. There is scarcely a protozoal disease of man which cannot be cured nowadays by early treatment with the appropriate synthetic drug. (Sleeping sickness, malaria, amœbic dysentery, leishmaniasis.) Epizootics resembling human diseases, as for example, trypanoses, are also relatively easily dealt with by the same drugs as have been found of value in the treatment of disease in man. On the other hand, there has been a lack of success, up to the present, in the treatment of those diseases of animals which are not generally related to the tropical diseases of man. The most important of these epizootics are the piroplasmoses, which are caused by babesiæ and theileriæ and which are found, not only in tropical and subtropical regions, but also in temperate zones. In this paper the discovery of a new remedy against piroplasmosis will be reported (acaprin). Further, advice will be given of a new class of substances, which have an actual chemotherapeutic action in streptococcal infections (prontosil, prontosil S), so that one can hope to be able in the future also to attack bacterial infections due to cocci chemotherapeutically.

Amino acid metabolism in Ancylostoma ceylanicum and Nippostrongylus brasiliensis

1987 ◽  
Vol 61 (1) ◽  
pp. 84-88 ◽  
Author(s):  
Govind Singh ◽  
Suman Gupta ◽  
J. C. Katiyar ◽  
V. M. L Srivastava
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
The Other ◽  
Nippostrongylus Brasiliensis ◽  
Ancylostoma Ceylanicum ◽  
Other Hand

ABSTRACTAncylostoma ceylanicum and Nippostrongylus brasiliensis decarboxylated most of the amino acids examined, but only a few at signficant rates. The former nematode in general possessed higher activites. Striking differences between the two parasites were, however, noticed regarding the metabolism of some of the amino acids. For instance, while alanine followed by asparate produced highest amounts of 14CO2in the presence of A. ceylanicum, proline exhibited maximum decarboxlation in case of N. brasiliensis. Tyrosine, on the other hand, did not libreate detectable CO2with either parasite. Likewise, although large number of amino acids underwent transmination with 2-oxoglutarate, only some of them elicited appreciable activity for any two parasites.

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