Modification of functional arginine residues in purified bovine testicular hyaluronidase with butane-2,3-dione

Gacesa, Peter; Savitsky, Marc J.; Dodgson, K. S.; Olavesen, Anthony H.

doi:10.1016/0005-2744(81)90005-x

Cited by 16 publications

(5 citation statements)

References 23 publications

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“…More recently, recombinant human liver UGT1A6 was also found to be sensitive to 2,3-butanedione [27]. A similar anionic interaction between the carboxyl group of glucuronic acid in hyaluronic acid and hyaluronidase has also been described [109] and may indicate a conserved mechanism of interaction in UGTs and in other enzymes that bind substrates possessing structural similarity to UDP-GlcUA.…”

Section: Structural Studies Of Ugts 845mentioning

confidence: 87%

Structural and Functional Studies of Udp-Glucuronosyltransferases*

Radominska‐Pandya

Czernik

Little

et al. 1999

Drug Metabolism Reviews

446

358

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UDP-Glucuronosyltransferases (UGTs) are glycoproteins localized in the endoplasmic reticulum (ER) which catalyze the conjugation of a broad variety of lipophilic aglycon substrates with glucuronic acid using UDP-glucuronic acid (UDP-GIcUA) as the sugar donor. Glucuronidation is a major factor in the elimination of lipophilic compounds from the body. In this review, current information on the substrate specificities of UGT1A and 2B family isoforms is discussed. Recent findings with regard to UGT structure and topology are presented, including a dynamic topological model of UGTs in the ER. Evidence from experiments on UGT interactions with inhibitors directed at specific amino acids, photoaffinity labeling, and analysis of amino acid alignments suggest that UDP-GIcUA interacts with residues in both the N- and C-terminal domains, whereas aglycon binding sites are localized in the N-terminal domain. The amino acids identified so far as crucial for substrate binding and catalysis are arginine, lysine, histidine, proline, and residues containing carboxylic acid. Site-directed mutagenesis experiments are critical for unambiguous identification of the active-site architecture.

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Section: Structural Studies Of Ugts 845mentioning

confidence: 87%

Structural and Functional Studies of Udp-Glucuronosyltransferases*

Radominska‐Pandya

Czernik

Little

et al. 1999

Drug Metabolism Reviews

446

358

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“…However, in the present study the influence of each of the additives was shown to be pHdependent and their presence can dramatically alter the apparent pH optimum. Purified bovine testicular hyaluronidase activity was shown to be stimulated across the pH-activity profile by the addition of albumin or NaCl and by increased buffer ion concentration with a resultant shift in the pH optimum to a more acidic value [20,21]. Skin fibroblast N-acetylgalactosamine-6sulphatase activity has been reported to be stimulated by up to 3-fold by the addition of albumin [22].…”

Section: Discussionmentioning

confidence: 99%

Glucuronate-2-sulphatase activity in cultured human skin fibroblast homogenates

Freeman¹,

Hopwood²

1991

Biochemical Journal

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The optimization of the assay conditions to detect glucuronate-2-sulphatase (GS) activity present in cultured human skin fibroblast homogenates towards a heparin-derived disaccharide substrate O-(beta-D-glucuronic acid 2-sulphate)-(1----4)-D-O-2,5-anhydro[l-3H]mannitol 6-sulphate (GSMS) has shown that a complex relationship exists between pH, buffer composition, ionic strength and the influence of added BSA and salts (NaCl, Na2SO4, CuCl2 and ZnCl2) to achieve maximum sulphatase activity. Whereas albumin stimulated GS activity by more than 2-fold over the pH range 2.7-5.7, CuCl2 stimulated GS activity over the narrow pH range 3.0-4.2, and inhibited GS activity at higher pH. ZnCl2 stimulated GS activity more than 3-fold at pH 3.0 and by more than 10-fold at pH 4.8. NaCl inhibited GS activity at pH 3.0, while activity between pH 4.2 and 4.8 was stimulated by up to 10-fold, resulting in a shift in the observed pH optimum from 3.0 to 4.8 in the presence of 315 mM-NaCl. Skin fibroblast GS activity toward GSMS had apparent Km values of 0.5-1.2 microM at pH 3.0, and 27.0-33.2 microM at pH 4.8. Albumin stimulated GS activity at both low and high pH by an increase in the apparent Vmax. values without significant alteration in the respective Km values. At pH 4.8, NaCl stimulated GS activity as a result of an increase in Vmax. values. These observations raise the possibility that two forms of GS activity are present in skin fibroblast homogenates: a low-Km form that has a pH optimum of 3.0 and is stimulated by BSA and a high-Km form with a pH optimum of 4.8 which is stimulated by NaCl.

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“…The relative effectiveness of the various polymers depends primarily on the negative charge density rather than the chemical structure or conformation of the polyanions (Table 1). The primary importance of charge-density-related interactions between enzymes and proteoglycans is also seen in the anti-complement effects of various glycosaminoglycans [27][28][29], the ability of both heparin and chondroitin sulphate E to activate Hageman factor [30], and the interaction of bovine testicular hyaluronidase with its substrate [31]. In contrast, certain enzyme cofactors have been shown to be influenced by structural components of polysaccharides; antithrombin III has been shown to bind to a defined tetrasaccharide structure of heparin [32], and the binding of platelet factor 4 to different chondroitin sulphates is influenced by the type of uronic acid moiety encountered [33].…”

Section: Omementioning

confidence: 99%

Regulation of human mast cell tryptase. Effects of enzyme concentration, ionic strength and the structure and negative charge density of polysaccharides

Alter

Metcalfe

Bradford

et al. 1987

Biochemical Journal

131

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Tryptase was previously shown to undergo rapid inactivation under physiological conditions unless stabilized by the presence of heparin. The current study shows that increasing the concentration of free tryptase enhances the preservation of enzymic activity, consistent with dissociation of the tetramer, rather than autodegradation, as the mechanism of inactivation. Heparin glycosaminoglycan fragments of Mr greater than 5700 are necessary for complete stabilization of tryptase activity. This stabilizing effect depends upon negative charge density rather than carbohydrate composition. Thus, keratan sulphate or hyaluronic acid were no better than physiological buffer alone; chondroitin monosulphates and heparan sulphate each prolonged the t1/2 about 20-fold over buffer alone; chondroitin sulphate E prolonged the t1/2 69-fold; and dextran sulphate and heparin provided complete stabilization of tryptase activity for 120 min. Poly-D-glutamic acid prolonged the t1/2 55-fold. In each case the loss of tryptase activity followed apparent first-order kinetics. Increasing the NaCl concentration from 0.01 M to 1.0 M increased the stability of free tryptase. In contrast, increasing the NaCl concentration in the presence of stabilizing polysaccharides decreased the stability of tryptase until dissociation of tryptase from each polysaccharide presumably occurred; thereafter tryptase stability increased as did that of free tryptase. The effect of salt concentration on heparin-stabilized tryptase activity (as opposed to stability) was also evaluated. The mast cell proteoglycans heparin and chondroitin sulphate E, by virtue of containing the naturally occurring glycosaminoglycans of highest negative charge density, may play a major role in the regulation of mast cell tryptase activity in vivo.

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Modification of functional arginine residues in purified bovine testicular hyaluronidase with butane-2,3-dione

Cited by 16 publications

References 23 publications

Structural and Functional Studies of Udp-Glucuronosyltransferases*

Structural and Functional Studies of Udp-Glucuronosyltransferases*

Glucuronate-2-sulphatase activity in cultured human skin fibroblast homogenates

Regulation of human mast cell tryptase. Effects of enzyme concentration, ionic strength and the structure and negative charge density of polysaccharides

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