Use of concanavalin a as a topographical probe for protein-protein interaction Application to lactose synthase

Wong, Shan S.; Malone, Thomas E.; Lee, Timothy K.

doi:10.1016/0167-4838(83)90173-5

Cited by 8 publications

(4 citation statements)

References 29 publications

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“…We have recently shown that the binding of concanavalin A to the carbohydrate moiety of galactosyltransferase does not inhibit the formation of the lactose synthase complex nor affect the activity of the enzyme. Therefore, we speculated that the active site and the protein-protein interaction site might overlap (Wong et al, 1983). Using photoaffinity labeling, we have demonstrated that -lactalbumin does not interact at the UDP-galactose binding domain (Lee et al, 1983).…”

mentioning

confidence: 99%

“…Materials and Methods Materials. Bovine milk galactosyltransferase and a-lactalbumin were purified as described earlier (Wong et al, 1983). Pyruvate kinase (type I), UDP-galactose, a-D-glucose and /3-D-glucose, NADH, and phosphoenolpyruvate were obtained from Sigma, and GlcNAc was from Pfanstiehl.…”

mentioning

confidence: 99%

“…Enzyme Kinetics. Galactosyltransferase and lactose synthase activities were followed spectrophotometrically as described earlier (Wong et al, 1983). Inhibition kinetics were performed by varying the concentration of the GlcNAc substrate analogues at various fixed concentrations of a-lactalbumin.…”

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confidence: 99%

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Association-dissociation modulation of enzyme activity: case of lactose synthase

Lambright¹,

Lee²,

Wong³

1985

Biochemistry

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Lactose synthase was found to show anomeric preference for beta-D-glucose. This information was utilized in the design of methyl, ethyl, propyl, butyl, and pentyl N-acetyl-beta-D-glucosaminides, which were subsequently demonstrated to be substrates for galactosyltransferase with apparent Km values in the low millimolar range. alpha-Lactalbumin competitively inhibits the transferase activity against these N-acetylglucosamine derivatives. This pattern of inhibition has also been observed when the dimer, trimer, and tetramer of N-acetylglucosamine and ovomucoid served as the galactose acceptor. The data suggest that the binding of alpha-lactalbumin and the N-acetylglucosamine derivatives is mutually exclusive. This assertion is further supported by the inability of methyl and butyl N-acetyl-beta-D-glucosaminides to facilitate retention of galactosyltransferase on a column of alpha-lactalbumin immobilized onto Sepharose. Free N-acetylglucosamine, on the other hand, does cause retention of the transferase under the same conditions. Thus, alpha-lactalbumin must bind to a region on galactosyltransferase in close proximity to the monosaccharide binding site and exert its substrate-specifying action through competitive and mutually exclusive binding with the N-acetylglucosamine analogues accompanied by an increased affinity for glucose. In short, our substrate analogue studies have revealed that the association-dissociation modulation of galactosyltransferase activity is effected through a topographical blockade of glycoprotein binding by alpha-lactalbumin.

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Association-dissociation modulation of enzyme activity: case of lactose synthase

Lambright¹,

Lee²,

Wong³

1985

Biochemistry

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“…ConA (MW 25700 for one subunit) is a glucose-binding protein which is composed of four identical subunits under basic conditions (pH > 7) [39]. Each subunit has one sugar-binding site which includes two tyrosine residues (tyrosine-12 and tyrosine-100) [40,41] (Scheme 9).…”

Section: Bioaffinity Of 5 Toward Concanavalin Amentioning

confidence: 99%

Water-Solubilization of P(V) and Sb(V) Porphyrins and Their Photobiological Application

Matsumoto

Shiragami

Hirakawa

et al. 2015

International Journal of Photoenergy

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Porphyrins have been widely utilized as biochemical and biological functional chromophores which can operate under visible-light irradiation. Water-soluble porphyrins have been used as the drug for photodynamic therapy (PDT) and photodynamic inactivation (PDI). Although usual water-solubilization of porphyrins has been achieved by an introduction of an ionic group such as ammonium, pyridinium, sulfonate, phosphonium, or carboxyl to porphyrin ring, we proposed the preparation of water-soluble P and Sb porphyrins by modification of axial ligands. Alkyl (type A), ethylenedioxy (type E), pyridinium (type P), and glucosyl groups (type G) were introduced to axial ligands of Sb and P porphyrins to achieve water-solubilization of Sb porphyrin and P porphyrins. Here, we review their water-soluble P and Sb porphyrins from the standpoints of preparation, bioaffinity, and photosensitized inactivation.

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The sulfhydryl group microenvironment of lactose synthase from bovine milk

Wong

1984

International Journal of Biochemistry

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Use of concanavalin a as a topographical probe for protein-protein interaction Application to lactose synthase

Cited by 8 publications

References 29 publications

Association-dissociation modulation of enzyme activity: case of lactose synthase

Association-dissociation modulation of enzyme activity: case of lactose synthase

Water-Solubilization of P(V) and Sb(V) Porphyrins and Their Photobiological Application

The sulfhydryl group microenvironment of lactose synthase from bovine milk

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