A Mucopolysaccharide that do not contain uronic acid (UA)
Ans. d (Keratan Sulphate) (Ref. Harper's Biochemistry-26th ed. 544 and 27th ed. 553)Mucopolysaccharides constitute a major part of connective tissue and consist of units of disaccharides, nitrogen, and sulfate groups. In mucopolysaccharidoses, acid polysaccharides are abnormally deposited in the tissues and excreted in the urine. Acid mucopolysaccharide yield N5 acetyl-hexosamine (a substituted sugar) and uronic acid. Neutral mucopolysaccharides comprise of N5 acetyl-hexosamine and a hexose. Major acid mucopolysaccharides are hyaluronic acid, chondroitin sulphate, chondroitin 6-sulfate, dermatan sulfate, heparan, and heparin. Keratan sulfate (of cornea or bones) is neutral mucopolysaccharide.GAGSugarsSulfateLinkage of proteinLocationHAGIcNAc, GlcUANilNo firm evidenceSynovial fluid, humor, loose connective tissueCSGalcNAc, GlcUAGalNAcXyl-Ser; associated with HA via link proteinsCartilage, bone, corneaKSIIGlcNAc, GalGIcNAcGlcNAc-AsnCorneaKSIGlcNAc, GalSame as KSIGlcNAc-ThrLoose connective tissueHeparinGlcN, ldUAGlcNSerMast cells GlcN ldUA HaparanGlcN, GlclIAGlcNXyl-SerSkin fibroblasts, aortic wallsulphateGalNAC, IdUAGalNAcXyl-SerWide distribution (GLCUA)ldUa Educational points:NameAlternative designatorsEnzyme defectUrinary metabolitesMucopolysaccharidosesHurler, Scheie,MPSIa-L-iduronidaseDermatan sulfate, heparan sulfateHurler-ScheieHunterSanfilippo AMPSIIMPS IMAIduronate sulfataseHeparan sulfateN-sulfatase (sulfamidase)Dermatan sulfate, heparan sulfateHeparan sulfateSanfilippo BMPS IIIBa-N-AcetylglucosaminidaseHeparan sulfateSanfilippo CMPS MICAcetyltransferaseHeparan sulfateSanfilippo DMPS MIDN-Acetylglucosamine 6-sulfataseHeparan sulfateMorquio AMPS IVAGalactosamine 6-sulfataseKeratan sulfate, chondroitin 6 sulfateMorquio BMPS IVBb-GalactosidaseKeratan sulfateMaroteaux - LamyMPS VIN-Acetylgalactosamine 4- sulfatase (arysulfatase B)Dermatan sulfateSlyMPS VIIb-GlucuronidaseDermatan sulfate, heparan sulfate chondroitin 4-sulfate, chondroitin 6- sulfateMucolipidosesSialidosis (MIM)ML ISialidaseGlycoprotein fragmentsI-cell disease (MIM)ML IIUDP-N-acetylglucosamine: glycoprotein N-acetylglucosami-ninylphosphotransferase. (Acid hydrolases thus lack phos-phomannosyl residues.) Pseudo-Hurler polydys- trophyML IIIAs for ML II but deficiency is incompleteGlycoprotein fragments
Heparin
Chondrotin sulphate
Dermatan sulphate
Keratan sulphate
Carbohydrates