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K L Matta

Publications and source records attributed to K L Matta.

At least 163 records · Page 9Linked to original sources
PubMed1983

Structural preferences of beta-galactoside-reactive lectins on Actinomyces viscosus T14V and Actinomyces naeslundii WVU45.

Specificities of lectins on Actinomyces viscosus T14V and Actinomyces naeslundii WVU45 were compared by measuring the abilities of D-galactose, N-acetyl-D-galactosamine, 14 beta-D-galacto-oligosaccharides, and 2 beta-D-fuco-oligosaccharides to inhibit coaggregation between Streptococcus sanguis 34 and each actinomycete. Inhibition profiles were similar, but WVU45 was significantly more sensitive to several inhibitors. D-Galactose-beta(1 leads to 3)-N-acetyl-D-galactosamine glycosides were most potent.

Actinomyces↗
PubMed1983

Mucin synthesis. III. UDP-GlcNAc:Gal beta 1-3(GlcNAc beta 1-6)GalNAc-R (GlcNAc to Gal) beta 3-N-acetylglucosaminyltransferase, an enzyme in porcine gastric mucosa involved in the elongation of mucin-type oligosaccharides.

Pig gastric mucosa microsomes have been shown to catalyze the following reaction: UDP-GlcNAc + Gal beta 1-3(GlcNAc beta 1-6)-GalNAc-alpha-R----GlcNAc beta 1-3Gal beta 1-3 (GlcNAc beta 1-6)GalNAc-alpha-R + UDP, where R is o-nitrophenyl or benzyl. The enzyme catalyzing this reaction has been named UDP-GlcNAc:Gal beta 1-3(GlcNAc beta 1-6)GalNAc-R (GlcNAc-R (GlcNAc to Gal) beta 3-N-acetylglucosaminyltransferase. The beta 3-GlcNAc-transferase does not act on Gal beta 1-3GalNAc-alpha-o-nitrophenyl. The beta 3-GlcNAc-transferase requires Mn2+ and Triton X-100 for optimal activity. The Vmax for the microsomal enzyme is 8.7 nmol/mg protein per hour and the Km values are 1.6, 0.9, and 1.2 mM for UDP-GlcNAc and the alpha-o-nitrophenyl and alpha-benzyl derivatives of Gal beta 1-3(GlcNAc beta 1-6)GalNAc, respectively. Pig gastric mucosa microsomes catalyze the transfer of GlcNAc to lactose to form GlcNAc beta 1-3Gal beta 1-4Glc, but fail to transfer GlcNAc to lactosyl ceramide, Gal beta 1-4GlcNAc, or Gal beta 1-4GlcNAc-beta-benzyl.

Animals↗
PubMed1983

Heat stability and pH activity data of alpha-L-fucosidase in human serum vary with enzyme concentration.

alpha-L-Fucosidase from serum of humans with either high or low enzyme activity was separately purified. the enzyme from either source had virtually the same heat stability and pH activity profile. It has been widely reported that alpha-L-fucosidase in crude sera from individuals with high and low enzyme activity differed with respect to heat stability and activity at pH 4 relative to activity at pH 5, the pH optimum of the enzyme. We investigated this discrepancy and found that both the heat stability and relative activity at pH 4 of alpha-L-fucosidase from sera with either high or low enzyme activity was dependent upon enzyme concentration. With decreasing enzyme concentration, the enzyme was more heat labile and had less relative activity at pH 4. Consequently, if the data obtained using high and low enzyme activity sera are compared on the basis of equivalent amounts of serum instead of equivalent amounts of enzyme activity, differences between the enzyme from high and low activity serum would be erroneously inferred. Apparently, this is what other investigators have done. Moreover, we found that alpha-L-fucosidase can exist in heat-stable or labile species with sedimentation coefficients of 9.8 S and 4.8 S, respectively. The interconversion and relative proportion of these species is dependent upon enzyme concentration and pH.

Centrifugation, Density Gradient↗
PubMed1981

The chemical synthesis of O-alpha-L-fucopyranosyl-(1 goes to 2)-O-beta-D-galactopyranosyl-(1 goes to 3)-O-[alpha-L-fucopyranosyl-(1 goes to 4)]-2-acetamido-2-deoxy-D-glucopyranose, the Lewis b blood-group antigenic determinant.

An approach has been developed for the rapid synthesis of benzyl 2-acetamido-2-deoxy-3-O-beta-D-galactopyranosyl-beta-D-glucopyranoside (5). Disaccharide 5 was per(trimethylsilyl)ated, to provide the fully protected trimethylsilyl (Me3Si) derivative which, on treatment with pyridine-acetic anhydride-acetic acid for 2 days, gave the disaccharide derivative having O-acetyl groups selectively at the primary positions and Me3Si groups at the secondary positions. The latter groups were readily cleaved by treatment with aqueous acetic acid in methanol, to afford benzyl 2-acetamido-6-O-acetyl-3-O-(6-O-acetyl-beta-D-galactopyranosyl)-2-deoxy-beta-D- glucopyranoside, which, is isopropylidenation, gave the desired, key intermediate 9, having two hydroxyl groups free. Condensation of 9 with 2,3,4-tri-O-benzyl-alpha-L-fucopyranosyl bromide, under catalysis by halide ion, afforded the tetrasaccharide derivative, from which the title tetrasaccharide was obtained by systematic removal of the protecting groups. The structure of the final product, and of various other intermediates, was established by 1H- and 13C-n.m.r. spectroscopy.

Carbohydrate Conformation↗
PubMed1981

Frequency of an allele for low activity of alpha-L-fucosidase in sera: possible increase in epithelial ovarian cancer patients.

Sera from a group of patients with ovarian cancer had a statistically significant deficiency of alpha-L-fucosidase activity compared with sera from healthy females or female patients with cervical or breast cancer. Mixing experiments did not identify an inhibitor of alpha-L-fucosidase activity in the sera of ovarian cancer patients. Decreased activity of alpha-L-fucosidases was not associated with stage of disease, tumor burden, histologic type, or grade of differentiation. Unlike alpha-L-fucosidase, beta-man-nosidase and beta-N-acetylglucosamindase in sera of ovarian cancer patients were not deficient in activity. Examination of population data of healthy females and of pedigrees of ovarian cancer patients suggested that the quantitative activity alpha-L-fucosidase in serum was genetically determined. Of 60 healthy females, 4 had low enzyme activity (less than 100 U alpha-L-fucosidase/ml serum), 26 had intermediate activity (100-274 U alpha-L-fucosidase/ml), and 30 had high activity (275 U/ml), whereas of 44 ovarian cancer patients, 11 had low, 29 had intermediate, and 4 had high activity. Application of the Hardy-Weinberg law to these data revealed that low enzyme activity in sera was three times more prevalent in the ovarian cancer group, the allele for this low enzyme activity being two times more common. These observations suggested that deficiency of alpha-L-fucosidase activity in sera of females may be a hereditary condition associated with increased risk for development of ovarian cancer.

Acetylglucosaminidase↗
PubMed1980

Mucin synthesis. II. Substrate specificity and product identification studies on canine submaxillary gland UDP-GlcNAc:Gal beta 1-3GalNAc(GlcNAc leads to GalNAc) beta 6-N-acetylglucosaminyltransferase.

The preceding paper (Williams, D., and Schachter, H. (1980) J. Biol. Chem. 255, 0000-0000) described a novel N-acetylglucosaminyltransferase in canine submaxillary gland microsomes which catalyzed the incorporation of GlcNAc into mucin acceptors. We show in the present report that the enzyme catalyzes th following reaction: UDP-GlcNAc + Gal beta 1-3GalNAc-X leads to Gal beta 1-3(GlcNAc beta 1-6) GalNAc-X + UDP, where X can be porcine submaxillary mucin polypeptide (Km = 5.2 mM), antifreeze glycoprotein polypeptide (Km = 23 mM), alpha-O-p-nitrophenyl (Km = 0.52 mM), beta-O-p-nitrophenyl (Km = 0.92 mM), alpha-O-o-nitrophenyl (Km = 0.86 mM), alpha-O-benzyl (Km = 0.77 mM), alpha-O-methyl (Km = 4.2 mM), or -H (Km = 1.2 mM). Ineffective acceptors (< 5% of the activity with Gal beta 1-3GalNAc-alpha-p-nitrophenyl) are asialo-ovine submaxillary mucin, asialo-alpha 1 acid glycoprotein, Gal beta 1-3GlcNAc-beta-p-nitrophenyl, Gal beta 1-3GlcNAc-alpha-methyl, Gal beta1-3GlcNAc, Gal beta 1-3-N-acetylgalactosaminitol, and D-fucose beta 1-3GalNAc-alpha-benzyl, indicating that both the Gal and GalNAc residues are essential for acceptor activity. The beta 1 leads to 6-linkage of GlcNAc to GalNAc in the acceptor Gal beta 1-3GalNAc-alpha-O-benzyl was established by methylation analysis and high resolution 1H nuclear magnetic resonance spectroscopy of a large scale preparation of product. Preliminary evidence has been obtained indicating that sialic acid linked alpha 2-6 to GalNAc or L-fucose linked alpha 1-2 to Gal inhibit the action of the beta 6-N-acetylglucosaminyltransferase on Gal beta 1-3GalNAc-porcine submaxillary mucin polypeptide.

Animals↗
PubMed1980

Modified procedure for detection of GDP-L-fucose:galactoside 2'-fucosyltransferase.

A modified method was developed for determination of GDP-L-fucose: galactoside 2'-fucosyltransferase in human serum which employed O-nitrophenyl-beta-D-galactopyranoside, phenyl-2-acetamido-2-deoxy-3-O-beta-D-galactopyranosyl-alpha-D-galactopyranoside, or phenyl-beta-D-thiogalactopyranoside as acceptor. Products were identified and characterized by thin layer chromatography with authentic reference compounds and by hydrolysis with alpha-(1 leads to 2)-L-fucosidase. The principal advantages of this method over the previous procedure which used aryl galactoside acceptors, are elimination of the need for a radiochromatogram scanner to locate reaction products and a reduced development time for chromatography. These results in substantial time and cost savings. Moreover, our system can simultaneously monitor possible competing reactions which may interfere with determination of alpha-2-L-fucosyltransferase activity. These include phosphorylase and alpha-L-fucosidase activities and incorporation of [14C]-alpha-L-fucose into endogenous acceptors of enzyme preparations. thus, this modified procedure will facilitate determination of alpha-2-L-fucosyltransferase.

Chromatography, Thin Layer↗
PubMed1980

Rapid procedures for determination of endo-N-acetyl-alpha-D-galactosaminidase in Clostridium perfringens, and of the substrate specificity of exo-beta-D-galactosidases.

Culture fluid of Clostridium perfringens hydrolyzed the synthetic, chromogenic substrates beta-Gal-(1 leads to 3)-alpha-GalNAc-1 leads to OPh and beta-Gal-(1 leads to 3)-alpha-GalNAc-1 leads to OC6H4-NO2-o or -p to beta-Gal-(1 leads to 3)-GalNAc and the aglycon. Such assays facilitated the characterization and purification of this endo-N-acetyl-alpha-D-galactosaminidase activity. This activity was purified 1200-fold by fractionation with ammonium sulfate and chromatography on columns of Sephadex-G200, DEAE-Sephadex, and hydroxylapatite. The final preparation showed activity over a broad range of pH, with an optimum at 9.0, but less-pure material had two pH optima, 4.0 and 9.0. Another assay method, which employed the synthetic, chromogenic substrates beta-Gal-(1 leads to 3)-beta-GlcNAc-1 leads to OC6H4NO2-p, beta-Gal-(1 leads to 4)-beta GlcNAc-1 leads to OC6H4NO2-p, and beta-Gal-(1 leads to 6)-beta-GlcNAc-1 leads to OC6H4NO2-p, was developed for the rapid identification of the linkage specificity of exo-beta-D-galactosidases from any source via a coupled reaction with N-acetyl-beta-D-hexosaminidase.

Acetylgalactosamine↗
PubMed1978

Action of endo-alpha-N-acetyl-D-galactosaminidase on synthetic glycosides including chromogenic substrates.

The synthetic glycosides, p-nitrophenyl- and o-nitrophenyl-2-acetamido-2-deoxy-3-O-beta-D-galactopyranosyl-alpha- D-galactopyranosides, were found to be effective chromogenic substrates for an endo-alpha-N-acetyl-D-galactosaminidase. We did not experience any problems when these substrates were used for the screening of column fractions during the purification of the endoenzyme from Diplococcus pneumoniae culture filtrates. However, it should be pointed out that a combination of exo-beta-galactosidase, capable of cleaving beta 1-->3 linkages, and an exo-alpha-N-acetyl galactosaminidase would also liberate nitrophenol from the above substrates. The enzyme had no action on several other synthetic glycosides tested indicating the strict specificity of this enzyme for the disaccharide Gal beta-->GalNAc linked via an alpha-linkage to the aglycone. The enzyme was inactive when the aglycone was methanol but shows activity against the glycosides of phenol, nitrophenols, serine, and threonine. The use of p-nitrophenyl-2-acetamido-2-deoxy-3-O-beta -D-galactopyranosyl-beta-D-galactopyranoside, which is a competitive inhibitor of the endoenzyme, as an affinity ligand for the purification of the enzyme is described.

Affinity Labels↗
PubMed1977

Facile synthesis of 2-methyl-[4,6-di-O-acetyl-1,2-dideoxy-3-O-(2,3,4,6-tetra-O-acetyl-D-glycopyranosyl)-alpha-D-glucopyrano-[2',1':4,5]-2-oxazolines, key intermediates for the synthesis of oligosaccharides.

A simple synthesis of disaccharide oxazolines has been developed. Condensation of methyl 2-acetamido-4,6-O-benzylidene-2-deoxy-alpha-D-glucopyranoside with 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide, followed by removal of the 4,6-O-benzylidene group from the resulting disaccharide derivative, gave crystalline methyl 2-acetamido-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-alpha-D-glucpyranoside which, on acetolysis with acetic anhydride-acetic acid-sulfuric acid, provided 2-methyl-[4,6-di-O-acetyl-1,2-dideoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-alpha-D-glucopyrano]-[2',1':4,5]-2-oxazoline (7). Synthesis of the related alpha-D-mannopyranosyl compound was similarly accomplished. The glycosylating capability of 7 was employed for the synthesis of 6-(benzyloxycarbonylamino)hexyl-2-acetamido-4,6-di-O-acetyl-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-beta-D-glucopyranoside (18). An alternative synthesis of compound 18 is also described.

Glycosides↗
PubMed1977

Synthesis of p-nitrophenyl 6-O-(2-acetamido-2-deoxy-beta-d-glucopyranosyl)-beta-D-galactopyranoside and p-nitrophenyl O-beta-D-galactopyranosyl-(1 linked to 3)-O-(2-acetamido-2-dexoy-beta-D-glucopyranosyl)-(1 linked to 6)-beta-D-galactopyranoside.

Condensation of 2-methyl-(3,4,6-tri-O-acetyl-1,2-dideoxy-alpha-D-glucopyrano)-[2',1':4,5]-2-oxazoline with p-nitrophenyl 2,3-di-O-acetyl-beta-D-galactopyranoside (4), followed by saponification of the resulting disaccharide derivative, produced p-nitrophenyl 6-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-beta-D-galactopyranoside as a crystalline compound. Reaction of 2-methyl-[4,6-di-O-acetyl-1,2-dideoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-alpha-D-glucopyrano]-[2',1':4,5]-2-oxazoline with 4 in a similar reaction-sequence provided the title trisaccharide compound.

Disaccharides↗
PubMed1977

A comparison of the binding specificities of lectins from Ulex europaeus and Lotus tetragonolobus.

The L-fucose-binding lectins present in the seeds of Ulex europaeus and Lotus tetragonolobus have been isolated by affinity chromatography. The binding specificities of the lectins were compared by hemagglutination inhibition analysis. The lectins behaved similarly with respect to a variety of synthetic saccharides. D-Fucose derivatives were inactive as inhibitors. In general, the alpha -L-fucopyranosyl derivatives were better inhibitors than the beta-L-fucopyranosyl derivatives. Aromatic aglycones increased the inhibitory activity of the saccharides with p-nitrophenyl-alpha-L-fucopyranoside being one of the best inhibitors. The major difference between the two lectins was the observation that the Ulex lectin required higher concentrations of saccharides to bring about complete inhibition of hemagglutination than did the Lotus lectin.

ABO Blood-Group System↗