Glycoside Hydrolase Family 110 - Revision history

Spencer Williams at 03:16, 14 June 2011

2011-06-14T03:16:03Z

Harry Brumer: updated CAZy DB link

2011-05-09T13:25:02Z

updated CAZy DB link

Harry Brumer at 14:17, 8 November 2009

2009-11-08T14:17:57Z

Spencer Williams at 06:39, 6 September 2009

2009-09-06T06:39:20Z

Spencer Williams at 11:22, 3 September 2009

2009-09-03T11:22:52Z

Spencer Williams at 05:01, 1 September 2009

2009-09-01T05:01:13Z

Harry Brumer at 19:24, 30 July 2009

2009-07-30T19:24:36Z

Bernard Henrissat at 13:49, 10 July 2009

2009-07-10T13:49:48Z

Bernard Henrissat at 13:49, 10 July 2009

2009-07-10T13:49:17Z

Bernard Henrissat: /* Family Firsts */

2009-07-07T14:45:32Z

Family Firsts

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 == Substrate specificities ==
-This family of [[glycoside hydrolases]] was recently discovered following an effort to isolate enzymes for the selective and efficient removal of the terminal α-galactose residue on B antigen for the enzyme conversion of blood group B to universal group O <cite>#1</cite>. The activity of several enzymes has been studied and they display narrow substrate specificity for the branched blood group B oligosaccharide (Galα1–3(Fucα1–2)Gal). Interestingly and in contrast to many cases where glycosidases display a higher apparent activity on pNP-substrates than on oligosaccharides, the enzyme from ''B. fragilis'' NCTC 9343 (BfGal110A) exhibited a lower activity with pNP-α-Gal (0.3 U/mg) compared to the blood group B substrate (6.6 U/mg). The substrate specificity was remarkably stringent for α-1,3-linked galactose in the branched blood group B structure. The enzyme cleaved neither α4Gal linkages found in P1 and Pk blood group antigens nor the α3Gal linkage in the linear B structure without fucose (the so-called Galili antigen)<cite>1</cite>. In a subsequent study Liu et al. have shown the existence of two distinct subfamilies, one subfamily being exclusively active on the branched blood group B structures, whereas the other sufamily contained linkage specific α1,3-galactosidases that act equally well on both branched blood group B and linear α-1,3-Gal structures <cite>#2</cite>.
+This family of [[glycoside hydrolases]] was recently discovered following an effort to isolate enzymes for the selective and efficient removal of the terminal α-galactose residue on B antigen for the enzyme conversion of blood group B to universal group O <cite>#1</cite>. The activity of several enzymes has been studied and they display narrow substrate specificity for the branched blood group B oligosaccharide (Galα1–3(Fucα1–2)Gal). Interestingly and in contrast to many cases where glycosidases display a higher apparent activity on pNP-substrates than on oligosaccharides, the enzyme from ''B. fragilis'' NCTC 9343 (BfGal110A) exhibited a lower activity with pNP-α-Gal (0.3 U/mg) compared to the blood group B substrate (6.6 U/mg). The substrate specificity was remarkably stringent for α-1,3-linked galactose in the branched blood group B structure. The enzyme cleaved neither α4Gal linkages found in P1 and Pk blood group antigens nor the α3Gal linkage in the linear B structure without fucose (the so-called Galili antigen)<cite>1</cite>. In a subsequent study Liu et al. have shown the existence of two distinct subfamilies, one subfamily being exclusively active on the branched blood group B structures, whereas the other subfamily contained linkage specific α1,3-galactosidases that act equally well on both branched blood group B and linear α-1,3-Gal structures <cite>#2</cite>.
 == Kinetics and Mechanism ==
-The enzymes of this family are classified as [[inverting]] enzymes. The stereochemistry of hydrolysis has been monitored by <sup>1</sup>H NMR using pNP-α-Gal as the substrate and ''B. fragilis''BfGal110B as the enzyme. The results showed that the enzyme initially produces β-galactose, i.e. operates with overall inversion of the anomeric configuration, which is in striking contrast to all other known α-galactosidases that use a [[retaining]] mechanism (see  [[Glycoside Hydrolase Family 4]], [[Glycoside Hydrolase Family 27]], [[Glycoside Hydrolase Family 36]] and [[Glycoside Hydrolase Family 57]]) <cite>2</cite>.
+The enzymes of this family are classified as [[inverting]] enzymes. The stereochemistry of hydrolysis has been monitored by <sup>1</sup>H NMR using p-nitrophenyl α-galactoside as the substrate and ''B. fragilis''BfGal110B as the enzyme. The results showed that the enzyme initially produces β-galactose, i.e. operates with overall inversion of the anomeric configuration, which is in striking contrast to all other known α-galactosidases that use a [[retaining]] mechanism (see  [[Glycoside Hydrolase Family 4]], [[Glycoside Hydrolase Family 27]], [[Glycoside Hydrolase Family 36]] and [[Glycoside Hydrolase Family 57]]) <cite>2</cite>.
 == Catalytic Residues ==

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 |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
 |-
-| colspan="2" |http://www.cazy.org/fam/GH110.html
+| colspan="2" |{{CAZyDBlink}}GH110.html
 |}
 </div>

← Older revision		Revision as of 14:17, 8 November 2009
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		+	{{CuratorApproved}}
	* [[Author]]: [[User:Bernie\|Bernard Henrissat]]		* [[Author]]: [[User:Bernie\|Bernard Henrissat]]
	* [[Responsible Curator]]: [[User:Bernie\|Bernard Henrissat]]		* [[Responsible Curator]]: [[User:Bernie\|Bernard Henrissat]]

@@ Line 41: / Line 41: @@
 ;First sterochemistry determination: ''B. fragilis''BfGal110B by <sup>1</sup>H NMR <cite>2</cite>.
-;First [[catalytic nucleophile]] identification:
+;First [[general acid]] identification:
-;First [[general acid/base]] residue identification:
+;First [[general base]] residue identification:
 ;First 3-D structure:

@@ Line 41: / Line 41: @@
 ;First sterochemistry determination: ''B. fragilis''BfGal110B by <sup>1</sup>H NMR <cite>2</cite>.
-;First catalytic nucleophile identification:
+;First [[catalytic nucleophile]] identification:
-;First general acid/base residue identification:
+;First [[general acid/base]] residue identification:
 ;First 3-D structure:

← Older revision		Revision as of 19:24, 30 July 2009
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	</biblio>		</biblio>

−	[[Category:Glycoside Hydrolase Families]]	+	[[Category:Glycoside Hydrolase Families\|GH110]]

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 == Family Firsts ==
-;First sterochemistry determination: The stereochemistry of hydrolysis has been monitored by <sup>1</sup>H NMR using pNP-α-Gal as the substrate and ''B. fragilis'' BfGal110B as the enzyme. The results showed that the enzyme initially produces β-galactose, i.e. operates with overall inversion of the anomeric configuration, which is in striking contrast to all other known α-galactosidases that use a retaining mechanism (see  [[Glycoside Hydrolase Family 4]] [[Glycoside Hydrolase Family 27]] [[Glycoside Hydrolase Family 36]] and [[Glycoside Hydrolase Family 57]]) <cite>2</cite>.
+;First sterochemistry determination: The stereochemistry of hydrolysis has been monitored by <sup>1</sup>H NMR using pNP-α-Gal as the substrate and ''B. fragilis'' BfGal110B as the enzyme. The results showed that the enzyme initially produces β-galactose, i.e. operates with overall inversion of the anomeric configuration, which is in striking contrast to all other known α-galactosidases that use a retaining mechanism (see  [[Glycoside Hydrolase Family 4]], [[Glycoside Hydrolase Family 27]], [[Glycoside Hydrolase Family 36]] and [[Glycoside Hydrolase Family 57]]) <cite>2</cite>.
 ;First catalytic nucleophile identification:
 ;First general acid/base residue identification: