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N Seno

Publications and source records attributed to N Seno.

At least 91 records · Page 5Linked to original sources
PubMed1981

Linkage regions between dermatan polysulfates and peptides.

Three different types of dermatan polysulfate peptides I, II and III, isolated from hagfish notochord, hagfish skin and shark skin, all contained serine, xylose and galactose in a molar ratio of about 1.2 : 1 : 2. After beta-elimination-reduction, dermatan polysulfate peptides II and III produced alanine and xylitol in amounts equivalent to the amount of the serine decrease. Accordingly, it was shown that these dermatan polysulfates were linked to peptides by O-glycosidic bond between xylose and serine, as in chondroitin sulfates and dermatan sulfate. However, dermatan polysulfate peptide I produced N-acetylgalactosaminitol, in addition to alanine and xylitol, in a molar ratio of about 2 : 3 : 1, although the increase of alanine was equivalent to the serine decrease. Consequently, it was concluded that the linkage region of dermatan polysulfate peptide I has two types of O-glycosidic bond: one between xylose and serine and the other between N-acetylgalactosamine and serine. This is the first finding of an N-acetylgalactosamine involved in the linkage region of glycosaminoglycans consisting of uronic acid as repeating constituents.

Amino Acids↗
PubMed1981

Change of drug resistance patterns and genetic properties of R plasmids in Salmonella typhimurium of bovine origin isolated from 1970 to 1979 in northern Japan.

A total of 321 Salmonella typhimurium strains of bovine origin obtained in northern Japan during the period 1970-1979 were tested for drug resistance and detection of conjugative R plasmids. Three hundred and eighteen (99.1%) of these strains were resistant to one or more drugs. The isolation frequently of multiply drug-resistant strains tended to increase year by year. Two hundred and thirty-seven (74.5%) of these resistant strains carried conjugative R plasmids. A total of 308 R plasmids including 174 (56.5%) thermosensitive (ts) R plasmids were derived from the 237 drug-resistant strains, indicating that 71 (30.0%) strains have two different conjugative R plasmids in a single host cell. Of the 308 R plasmids examined for fertility inhibition (fi), 167 ts and 131 non-ts R plasmids were fi-. Of the 60 ts r plasmids examined for incompatibility, 50 were classified into H1 group and 10 into H2 group. Of the 52 non-ts R plasmids examined, 35 were classified into the I alpha-group and the remaining plasmids were untypable in our tests. Mercury resistance marker was found in about 20% of H1 R plasmids coding for multiresistance, and all of H2 R plasmids coded for resistance to tellurite. The clonal distribution of an S. typhimurium strain which carried an H1 R plasmid coding for resistance to six drugs and mercury was recognized in 1978 and 1979.

Animals↗
PubMed1980

Amination and subsequent derivatization of epoxy-activated agarose for the preparation of new affinity adsorbents.

We have found a simple procedure to convert epoxy-activated agarose into amino derivatives using ammonia solution. The amino derivatives of agarose were succinylated with succinic anhydride and then activated with N-hydroxysuccinimide according to the method of Cuatrecasas and Parikh. Formula: (See Text). Coupling of the ligand to the activated agarose (shown above) was performed under mild conditions. The adsorbent thus obtained has no charged group in the linkage region between the ligand and agarose, thus reducing the nonspecific adsorption, and the bonds formed (ether and amide bonds) are stable even in an alkaline medium. Lens culinaris hemagglutinin-Sepharose 4B prepared by this method was successfully used for the affinity chromatography of solubilized human red blood cell membrane in detergent solution and was stable when elution was performed with borate buffer, pH 9.8.

Amination↗
PubMed1980

Detection of lectin-sugar interaction by ultraviolet difference spectroscopy.

It was found that the addition of specific sugars to solutions of several lectins induced ultraviolet difference spectra. The difference spectra of lectins from Lens culinaris, Sophora japonica, Solanum tuberosum and wheat germ have two peaks at 292 nm and 284-287 nm which are characteristic of the tryptophanyl residue. The difference spectrum of Arachis hypogaea agglutinin has two peaks at 285 nm and 279 nm which seem to be characteristic of the tyrosyl residue. In addition to the identification of these amino acid residues as being in or near the sugar binding sites of the lectins, the binding constants of these lectins with the specific sugars can be easily determined from the intensities of the difference spectra at various concentrations of sugars. This method may be useful for the simple and direct determination of the binding constants of lectins with various naturally occurring sugars which have no chromogenic groups.

Carbohydrates↗
PubMed1979

Activation of Sepharose with epichlorohydrin and subsequent immobilization of ligand for affinity adsorbent.

The optimal conditions for the activation of Sepharose by epichlorohydrin and subsequent immobilization of ligands were investigated. Under the optimal conditions for activation, namely, 30% Sepharose-5% epichlorohydrin-0.4 M NaOH, 40 degrees C, 2 h, the maximum amount of epoxy group was introduced into Sepharose with low cross-linking. The absorbents obtained by using N-acetyl-D-glucosamine, tri-N-acetylchitotriose, and glycoprotein as a ligand exhibited no nonspecific adsorption and good permeability for the high molecular substance to be purified, and were stable in an alkaline solution. Solanum tuberosum agglutinin was specifically adsorbed on a tri-N-acetylchitotriose-Sepharose column and was quantitatively recovered by elution with 0.2 M ammonia solution. Furthermore, the column could be repeatedly used under these conditions without reduction of its capacity.

Acetylglucosamine↗
PubMed1978

Presynaptic inhibitory effects of catecholamines on cholinergic transmission in the smooth muscle of the chick stomach.

In the vagus nerve--smooth muscle preparation isolated from the chick proventriculus, adrenaline, clonidine (10(-8) - 2.5 x 10(-7) M), noradrenaline (10(-7) - 2.5 x 10(-6) M) and dopamine (10(-5) - 10(-4) M) inhibited the contraction induced by low frequency (0.5 Hz) stimulation of the vagus nerve, but they did not inhibit the contraction elicited by acetylcholine (5 x 10(-8) - 5 x 10(-7) M). The concentration producing 50% inhibition was 10(-7) M for adrenaline and clonidine, 10(-6) M for noradrenaline, and 5 x 10(-5) M for dopamine. Isoproterenol (5 x 10(-8) - 5 x 10(-7) M) inhibited the responses induced by both stimulation of the vagus nerve and acetylcholine. The inhibitory effects of the catecholamine and clonidine were blocked by phentolamine (2.7 x 10(-6) M) but not by 5-(3-tert-Butylamino-2-hydroxy)-propoxy-3, 4-dihydrocarbostyril hydrochloride (OPC 1085) which blocked the effect of isoproterenol. It is suggested that presynaptic alpha-receptors are present in the myenteric plexus of the chick proventriculus, and that the catecholamines and clonidine exert their inhibitory effects on cholinergic transmission via these receptors.

Animals↗
PubMed1978

Structure of linkage region between chondroitin polysulfates and peptides.

Three different types of chondroitin polysulfate-peptide, chondroitin sulfate D-peptide, chondroitin sulfate E-peptide, and chondroitin sulfate K-peptide, all contained xylose, galactose, and serine in a molar ratio of about 1 : 2 : 1. After treatment with alkali in the presence of NaBH4 and PdCl2, they produced alanine and xylitol in amounts equivalent to the decrease in the amount of serine. Consequently, it was proved that these chondroitin polysulfates are all linked to peptides by O-glycosidic bonds between xylose and serine, as in chondroitin sulfates A and C. It is suggested that the carbohydrate-peptide linkage regions have the same structure in all the chondroitin sulfates, regardless of differences in the structure of the polysaccharide chains, such as the position of sulfate groups and the degree of sulfation.

Amino Acids↗
PubMed1975

Microheterogeneity of chondroitin sulfates from various cartilages.

Chondroitin sulfate fractions were isolated from different animal cartilages, including whale, cattle, sheep, ray and shark, by Dowex 1 chromatography followed by ethanol fractionation. Although each preparation showed a single spot when electrophoresed on cellulose acetate, both 4- and 6-sulfated disaccharides were present in chondroitinase digests of each. In particular, the main fraction of bovine tracheal chondroitin sulfate (SO4/Ga1N = 1) gave both the disaccharides in nearly equal amounts, and its IR spectrum showed absorption bands at 820 and 850 cm-1. This fraction yielded three types of tetrasaccharides after digestion with testicular hyaluronidase. Structural studies on these tetrasaccharides, using P. vulgaris chondro-4-sulfatase followed by chondroitinase, showed that one of them is a hybrid consisting of the 4- and 6-sulfated residues. In the light of these facts, a nomenclature for chondroitin sulfates is discussed.

Animals↗