Transcript Biochemistry- Ch 11. Carbohydrates

BiochemistryCh 11. Carbohydrates (Cont.)
阮雪芬
NTUT
Nov 18, 2002
ABO Blood Groups
Glycosidic Bonds Between Proteins
and Carbohydrates
N-linked Oligosaccharides
N-linked Oligosaccharides
Elastase
Protein Glycosylation Takes Place in
the Lumen of the Endoplasmic
Reticulum and in th Goligi Complex
Transport Into The Endoplasmic
Reticulum
Golgi Complex as Sorting Center
Formation of a Mannose 6phosphate Marker
 I-cell Disease: deficient in the phosphotransferase.
Quality-control System for The
Protein Folding in the ER
Mass Spectrometric “sequencing” of
Oligosaccharides
Peptide N-glycosidase F
Peptide N-glycosidase F,
neuraminidase F and b1, 4-galatosidase
Binding Selectivities of Plant Lectins
 Lectins are ubiquitous, being found in
animals, plants, and microorganisms.
 The chief of lectins in animals is to facilitate
cell-cell contact.
C-type in Animals
 A calcium ion acts as a bridge between the
protein and sugar through direct interactions
with sugar hydroxyl groups.
Selectins Mediate Cell-cell
Interactions
 L: lymph-node
vessels
 E: endothelium
 P: activated
blood platelets
Structure of A Part of Influenza
Hemagglutinin
 Influenza virus
recognizes sialic acid
residues present on
cell-surface
glycoproteins. The
viral protein that
binds to these sugars
is called
hemagglutinin.
Neuraminidase
 Another viral protein, neuraminidase,
cleaves the glycosidic bonds to the sialic
acid residues, freeing the virus to infect the
cell.
 Inhibitor of this enzyme are showing some
promise as anti-influenza agents.