BIOCHEMISTRYANDMOLECULARBIOLOGYChapter 19glycolipid metabolismDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Chapter 19 glycolipid metabolism
BIOCHEMISTRYANDMOLECULARBIOLOGYOutline*Overview*Function of glycolipid*Structure ofglycosphingolipid*Synthesis of glycosphingolipid*Degradation ofglycoshpingolipid*SphingolipidosesDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Outline *Overview *Function of glycolipid *Structure of glycosphingolipid *Synthesis of glycosphingolipid *Degradation of glycoshpingolipid *Sphingolipidoses
BIOCHEMISTRYANDMOLECULARBIOLOGY1.overviewLike the phospholipid sphingomyelin, almost allglycolipids are derivatives of ceramides in which amolecule of fatty acid is attached to the aminoalcohol.sphingosine. They are therefore more precisely calledglycosphingolipidsDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Like the phospholipid sphingomyelin, almost all glycolipids are derivatives of ceramides in which a molecule of fatty acid is attached to the aminoalcohol, sphingosine. They are therefore more precisely called glycosphingolipids. 1. overview
BIOCHEMISTRYANDMOLECULARBIOLOGY2.Functionofglycolipid>Components of all membranes in the body, found in greatestamounts in nerve tissue>Regulation of cellular interactions, growth, and developmentA source of blood group antigens, various embryonic antigensspecific for particular stages of fetal development , and sometumor antigens>Cell surface receptors for cholera and diphtheria toxinsas well as for certain viruses.Department of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY ➢Components of all membranes in the body, found in greatest amounts in nerve tissue. ➢Regulation of cellular interactions, growth, and development. A source of blood group antigens, various embryonic antigens specific for particular stages of fetal development , and some tumor antigens. ➢Cell surface receptors for cholera and diphtheria toxins, as well as for certain viruses. 2. Function of glycolipid
BIOCHEMISTRYANDMOLECULARBIOLOGY2.Functionof glycolipidWhen cell lose control of cell division and growth, there is adramatic change in the glycosphingolipid composition of themembrane.>Genetic disorders associated with an inability to properlydegrade the glycosphingolipids can result in inrtacellularaccumulation of these compounds leading to serious impairmentof the nervous system and development.Department of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY ➢When cell lose control of cell division and growth, there is a dramatic change in the glycosphingolipid composition of the membrane. ➢Genetic disorders associated with an inability to properly degrade the glycosphingolipids can result in inrtacellular accumulation of these compounds leading to serious impairment of the nervous system and development. 2. Function of glycolipid
BIOCHEMISTRYANDMOLECULARBIOLOGY3.Structure of glycosphingolipidA.Neutral glycosphingolipidsThe simplest neutral glycosphingolipids are the cerebrosidesB.Acidic glycosphingolipidsThe negative charge is provided by N-acetylneuraminic acidingangliosidesC.SulfatideSulfoglycosphingolipids( sulfatides) are found predominantlyinnervous tissue.Department of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY A. Neutral glycosphingolipids The simplest neutral glycosphingolipids are the cerebrosides. B. Acidic glycosphingolipids The negative charge is provided by N-acetylneuraminic acid in gangliosides. C. Sulfatide Sulfoglycosphingolipids( sulfatides) are found predominantly in nervous tissue. 3. Structure of glycosphingolipid
ARBIOLOGYO-GlycosidicbondCHOHHHHOC-C-C-C-CH2OH1HNHOHOHHH-AWNAAAOECIHOHGalactoseCeramide(polarnead)(hydrophoblcta)Figure17.14Stnucture ofa neutral glyco-sphingoipidgalactccerebrosideisafattyacidhydrocarbonchain).veparunent ui Diucermsury anu iviuiecular Diuugy, iviedicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY
CERAMIDEAULARBIOLOGYN-AcetviEactoamn-舌舌--SH工1GIUCOOHSHOHalectcseAAN-Acetyineuramlinlcacid(NANA)Figure17.15MedicineSchoolStructure of the ganglioside Gm2-
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY
ANHJLARBIOLOGY05-0-P-O-CHOOH0O-P=OOFigure17.16Structureof3'-phosphoadenosine-5'-phosphosulfate(PAPS)Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY
ACERAMIDEDLECULARBIOLOGYAWWO=C-HN-CHCH-OHOn-GalacoseOSOHHHOHFigure17.17Structure of galactocerebroside 3-logy,MedicineSchoolsulfate
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY