amylose

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amylose
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Amylopectin or glycogen
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Glycogen and Amylopectin Structures
Glycogen and Amylopectin are a(1-4) chains
with with a(1-6) branches
Polysaccharides
Amylopectin
Glycogen
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cellulose
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cellulose
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Carbohydrates Complex (Polysaccharides)
Cellulose polysaccharide
found in plant
cell walls
Cellulose fibers
Macrofibril
Microfibril
Chains of cellulose
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chitin
N-acetyl-D-glucosamine units in (b--gt4) linkage
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Glycoprotein

• Glycoproteins are proteins that contain
  oligosaccharide chains (glycans) covalently
  attached to their polypeptide side-chains.
• The process of attaching the glycans is known as
  glycosalation.
• The sugar groups attached to glycoprotein can
  assist in protein folding or improve a proteins
  stability.

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Functions of Glycoproteins
Function Glycoprotein
Structural Molecule Collagen
Lubricant and Protective Agent Mucins
Transport Molecule Transferrin, ceruloplasmin
Immunologic Molecule Immunoglobins, histocompatibility antigens
Enzyme Various, e.g alkaline phosphatase
Cell Attachment-recognition site Proteins involved in cell to cellc ommunication
Interact with specific carbohydrates Lectins, selectins (cell adhesion lectins), antibodies
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Functions of Glycoproteins
Function Glycoprotein
Receptor Various Proteins in hormone and drug action
Affect folding of certain proteins Calnexin, Calreticulin
Regulation of development Notch and its analogs, key proteins in development
Hemostasis (and thrombosis) Specific glycoproteins on the surface membranes of platelets
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glycosaminoglycans of extracellular matrix
lubricants in the synovial fluid of joints
cartilage, tendons, ligaments
a variety of horny structures formed of dead
cells horn, hair, hoofs, nails
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Proteoglycans cell surface or extracellular
matrix
A typical tetrasaccharide linker (blue) connects
a glycosamino-glycanin this case chondroitin
4-sulfate (orange)to a Ser residue (pink) in the
core protein. The xylose residue at the reducing
end of the linker is joined by its anomeric
carbon to the hydroxyl of the Ser residue.
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Proteoglycan aggregate of the extracellular matrix
One very long molecule of hyaluronan is
associated noncovalently with about 100 molecules
of the core protein aggrecan
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Interactions between cells and the extracellular
matrix
with binding sites for both integrin and the
proteoglycan
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linkages in glycoproteins
Ser/thr
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Bacterial lipopolysaccharides
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Lectins, found in all organisms, are proteins
that bind carbohydrates with high specificity
cell-cell recognition, signaling, adhesion
processes, intracellular targeting, deterrent to
insects
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lectin-ligand interactions in lymphocyte movement
to the site of an infection
Stronger interaction near the site of inflammation
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Helicobacter pylori Interaction between a
bacterial surface lectin and an oligosaccharide
of the gastric epithelium
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Recognition and adhesion at the cell surface
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