Caramelization; It's all the RAGE Flashcards
Maillard reaction
reaction betwen aa and reducing sugar usually requiring heat
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CEL
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CML
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MG-H1
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Pyraline
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maillard rxn
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Glyoxal
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Methylglyoxal
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3-Deoxyglucosone
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GOLD
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MOLD
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DOLD
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pentosidine
Mailard reaction products
one family of post-translational modificaations on proteins that accumulate with age of the individual
these modifications are initiated by the non-enzymatic condensation between amino groups of protiens and reducing sugars such as glucose
the inital product is a schiff base, which udergoes amadori rearrangement to the amadori product
subsequent reactions of the amadori product
dehydration
rearrangement
fragmentation
condensation
to yield a variety of advanced maillard reaction end products
=AGEs
pyrraline and pentosidine
Protein modificaitons that stem fromt he maillard reaction
associated with cross-link formation and decreased protein solubility (wiht urea or guanidinium hydrochoride) lead to fibres and increased protease resistance
this is because proteins need to be soluable and monomeric to be degraded
also why we see aggregates with prion diseases
lead to disease conditions like alzheimers, diabetes complications, catarracts and degenerative eye diseases as well as extracellular matrix proteins
non-proteinacious AGEs
diseases are due to the accumulation of AGEs not only on proteins but on nucleic acids and lipids as well
describe the process of AGE formation
glucose reacts with amino groups of lysine and NH2 terminal amino acid residues
early stage reactions lead to the formation of fructosyl-lysine and releated fructoamine residues whic degrade slowly to form AGEs
In addtion to degredation of glycated proteins, glycolytic intermediates and lipid peroxidation lead to the formation of the reactive dicarbonyl metabolites
glyoxal
methyglyoxal
3-deoxyglucosone
Dicorbonyls
form AGE residues in proteins largely, but not exclusively on arginine residues
most abundant AGEs
the hydroimidazolones derived from
glyoxyl
methylglyoxal and 3-DG
aka dicarbonyls
lysine derived AGEs
CML and CEL
inidazolium AGEs
glyoxal
methyglyoxal
3-DG (MOLD GOLD DOLD)
RAGE
multiligand cell-surface receptors
binds to several distinct proinflammatory moleucles and has been implicated in the pathogenesis of diabetes and cardiovascular disease
as well as proteolytically cleaved isoforms shed into the bloodstream upon degestion of cell-surface RAGE bu extracellular metalloproteinases
