Search PubMed⌕ Search

Biomedical subjects

N Sharon

Publications and source records attributed to N Sharon.

At least 217 records · Page 12Linked to original sources
PubMed1976

Immunochemical studies on the specificity of the peanut (Arachis hypogaea) agglutinin.

The specificity of purified, peanut agglutinin has been studied immunochemically by quantitative precipitin and inhibition assays. The lectin showed substantial differences in precipitating with blood-group substances of the same specificity. Of the B substances tested, horse 4 25% completely precipitated the lectin, Beach phenol insoluble failed to interact, and PM phenol insoluble gave an intermediate reaction. The lectin did not precipitate with A1 substances, with hog gastric mucin A + H substance, or with A2 substance WG phenol insoluble. Another A2 substance, cyst 14 phenol insoluble, precipitated approximately 2/3 of the lectin. Of the H substances, Tighe phenol insoluble was inactive, JS phenol insoluble precipitated poorly, and morgan standard H precipitated about 80% of the lectin. However, first stage of Smith degradation, as well as Pl fractions obtained by mild acid hydrolysis of blood-group substances, gave products which precipitated strongly. The lectin was also completely precipitated by all precursor blood-group substances, as well as by cows 21 and 26, all having strong I-Ma, I-Ort, I-Step, and I-Da activities. Cow 18, which does not possess significant blood-group I activity, precipitated very slightly. Fractions of blood-group substances N-1 (Lea) and Tij (B) obtained by precipitation from 90 percent phenol at higher concentrations of ethanol interacted better with peanut agglutinin. These differences in activity are ascribable to a heterogeneity resulting from incomplete biosynthesis of carbohydrate side-chains of blood-group substances, particularly resulting in variations in the numbers of DGalbeta1 leads to 3DGalNAc or DGalbeta1 leads to 4DGlcNAc determinants. The agglutinin reacted with the hydatid cyst P1 glycoprotein, as well as with the previously studied antifreeze and sialic acid-free alpha1 acid glycoproteins, but not with pneumococcus type XIV polysaccharide. Inhibition of precipitation showed the lectin to be most specific for the disaccharide DGalbeta1 leads to 3DGalNAc, which is 14, 55, and 90 times as active as DGalbeta1 leads to 4DGlcNAc, DGal, and DGalbeta1 leads to 3DGlcNAc, respectively. DGalbeta1 leads to 3N-acetyl-D-galactosaminitol has approximately 1/25th the activity of DGalbeta1 leads to 3DGalNAc. Substitutions of DGlcNAc or LFuc on the DGal of active inhibitors completely blocked the activity, in line with the assumption that the combining site of the peanut lectin is a partial cavity. The oligosaccharides DGalbeta1 leads to 4DGlcNAcbeta1 leads to 6-hexane-1,2,4,5,6-pentol(s) and DGalbeta1 leads to 3[DGalbeta1 leads to 4DGlcNAcbeta1 leads to 6]N-acetyl-D-galactosaminitol showed the same inhibitory activity as DGalbeta1 leads to 4DGlcNAc, suggesting that the combining site of the peanut agglutinin may not be complementary to more than a disaccharide...

Animals↗
PubMed1976

The use of human foreskin cell cultures for isolation of herpesvirus group in the diagnostic laboratory.

Cell cultures originated from human foreskin (HFS) tissues were used for isolation of viruses from diagnostic specimens. The foreskins were collected in Hank's balanced salt solution and then processed on the same day by dispersion in trypsin. A week after the trypsin treatment of the tissues, the first cell cultures were ready to use. Continuous subcultures in vitro of the cells gave rise to a colony of cells that multiplied freely in vitro and supported the growth of viruses from the herpes group. In three cases tested in our laboratory in the last 6 months, viruses from the herpes group were isolated on the HES. The cytopathic changes of the HFS cells were observed 5 to 8 days after infection. They were not detected on two other human-origin cell cultures (WI-38 and HEp2) or on primary monkey kidney cells. The viruses isolated from these three cases were cytomegalovirus (CMV) from urine of a 2-week-old baby, a second CMV from a cutaneous lesion of a renal-transplant patient and herpes simplex virus from the eye swab of a young girl. After a few subcultures on the HFS cells, the three viruses produced CPE on the other susceptible human cells. The preparation of HFS cells is easy, the availability of the tissue is high, and the diagnostic value is unquestionable. It is suggested that this tissue and its cell cultures be used more often in diagnostic and research laboratories.

Adult↗
PubMed1975

The purification, composition, and specificity of the anti-T lectin from peanut (Arachis hypogaea).

Peanut agglutinin was purified by affinity chromatography on Sepharose-epsilon-aminocaproyl-beta-D-galactopyranosylamine. The purified lectin obtained in a yield of 150 mg/100 g of defatted peanut was homogeneous on polyacrylamide gel electrophoresis, ultracentrifugation, and gel filtration. This intrinsic sedimentation coefficient (So20,w) and the intrinsic diffusion coefficient (Do20,w) were estimated at pH 7.4 as 5.7 +/- 0.1 S and 5.0 X 10(-7) cm2s(-1), respectively. The molecular weight of the agglutinin, determined by sedimentation and diffusion and by gel filtration, was found to be 110,000. Disc gel electrophoresis and gel filtration, both in the presence of sodium dodecyl sulfate, gave a single component of Mr = 27,500 suggesting that the lectin is a tetramer composed of four subunits. Four alanine residues per 110,000 g were found by NH2-terminal analysis and the sequence of the five NH2-terminal amino acids was: ALa-Glu-Ser-Val-Thr. Each cycle in a sequenator gave a single amino acid, suggesting that the four subunits are identical. Peanut agglutinin does not contain covalently bound sugar; it is devoid of cysteine and cystine, low in methionine, histidine, and tryptophan, but rich in acidic and hydroxyamino acids. The lectin agglutinated erthrocytes of human ABO blood types equally well, but only after they have been treated with neuraminidase. Of the monosaccharides tested for inhibition of hemagglutination only D-galactose and alpha- and beta-D-galactosides were active. High inhibitory activity was found with the Discaccharide DGalbeta(1 in equilibrium 3)DGalNAc and with the disialylated glycoproteins: alpha1-acid glycoprotein, fetuin, glycophorin, and human blood group NN or MM antigen. These desialylated glycoproteins also reacted with the lectin to form precipitin bands in Ouchterlony double diffusion in agar.

Amino Acid Sequence↗
PubMed1975

Interaction of wheat-germ agglutinin with bacterial cells and cell-wall polymers.

Wheat germ agglutinin was found to agglutinate cells of Escherichia coli PAT 84, Micrococcus luteus, Staphylococcus aureus H, and of S. aureus 52A5, but not cells of S. aureus 52A2. Interaction of wheat germ agglutinin with a soluble linear peptidoglycan secreted by Micrococcus luteus and with the teichoic acid of S. aureus H was demonstrated by agar gel diffusion, quantitative precipitation and inhibition of hemagglutination of trypsinized rabbit erythrocytes. No interaction could be demonstrated with the teichoic acid from a phage-resistant mutant (S. aureus 52A2) which lacks A-acetyl-D-glucosamine residues. All interactions were specifically inhibited by low concentrations of chitotriose (GlcNAcbeta1 leads to 4GlcNAcbeta1 leads to 4GlcNAc) and the bacterial cell wall tetrasaccharide, GlcNAcbeta1 leads to 4MurNAcbeta1 leads to 4GlcNAcbeta1 leads to 4MurNAc. Hemagglutination-inhibition experiments showed that the linear peptidoglycan and the teichoic acid of S. aureus H were several thousand times more potent inhibitors of wheat germ agglutinin than was N-acetyl-D-glucosamine. Comparison of the efficiency of different saccharides in inhibition of hemagglutination and precipitation of polymers by wheat germ agglutinin, strongly suggests that secondary, non-specific interactions contribute to the binding of the lectin to the polymers.

Agglutination Tests↗
PubMed1975

Novel type of murein transglycosylase in Escherichia coli.

The purification and properties of a novel type of murein transglycosylase from Escherichia coli are described. The purified enzyme appears as a single band on sodium dodecyl sulfate-polyacrylamide gels and has an apparent molecular weight of approximately 65,000 as estimated by gel filtration and gel electrophoresis. It degrades pure murein sacculi from E. coli almost completely into low-molecular-weight products. The two prominent muropeptide fragments in the digest are the disaccharide-tripeptide N-acetylglucosamine-N-acetylmuramic acid-L-alanine-D-iso-glutamic acid-meso-diaminopimelic acid and the corresponding disaccharide-tetrapeptide N-acetylglucosamine-N-acetylmuramic acid-L-alanine-D-iso-glutamic acid-meso-diaminopimelic acid-D-alanine. The unique feature of these compounds is that the disaccharide has no reducing end group and that the muramic acid residue possesses an internal 1 leads to 6 anhydro linkage. The new lytic enzyme is designated as a murein: murein transglycosylase. Its possible role in the rearrangement of murein during cell growth and division is discussed.

Ammonium Sulfate↗
PubMed1975

Peanut agglutinin, a new mitogen that binds to galactosyl sites exposed after neuraminidase treatment.

Peanut agglutinin, purified by affinity chromatography, agglutinates lymphocytes from mouse, rat, guinea pig, and man only after their treatment with neuraminidase. However, it stimulates only neuraminidase-treated rat and human cells. A similar number cell surface receptors for peanut agglutinin was found on neuraminidase-treated rat and mouse lymphocytes although the latter cells were not stimulated by the lectin. Galactose specifically inhibited the agglutination and stimulation of lymphocytes by peanut agglutinin. Sequential treatment of lymphocytes with neuraminidase and beta-galactosidase markedly reduced the response of the cells to stimulation by peanut agglutinin, soybean agglutinin, and galactose oxidase. It is suggested that the same galactosyl residue may be the target for the initial step in triggering lymphocytes by the above mentioned mitogens.

Agglutination Tests↗