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7/24/2019 Olfaction and Perception
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Olfac ! on & Percep! on
Olfac ! on & Percep! on
7/24/2019 Olfaction and Perception
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"Press Release: The 2004 Nobel Prize in Physiology or Medicine".
Nobelprize.org. 19 Oct 2012 http://www.nobelprize.org/
nobel_prizes/medicine/laureates/2004/press.html
7/24/2019 Olfaction and Perception
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Odor molecules are generally:
Detectable ! Volatile!
< 300 g/mol
Hydrophobic/Hydrophilic
7/24/2019 Olfaction and Perception
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The Cell Surface
Hydrophillicend
Hydrophobic end
O
O
O
O
OP
O
OO
N
phosphatidylcholine
HO
NH2
OHsphingosine
HO
HN
OH
O
ceramide
O
HN
OH
O
P
O
O ON
sphingomyelin
HO
H
HH
cholesterol
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Phospholipid Bilayer
H2O
H2O
Cellular contents are isolatedfrom extracellular environment
7/24/2019 Olfaction and Perception
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Olfactory Receptors
and the
7-Transmembrane G-protein coupled receptor proteins (GCPR)
Extracellular Hydrophillic Region
Intracellular Hydrophillic Region
Receptorprotein
Lipid bilayer Cholesterol
Hydrophobic Region
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G-protein-coupled receptors (7-TM receptors)
Structure - Single protein with 7 transmembrane regions
Transmembranehelix
C -Terminal chain
G-Protein
binding region
Extracellular
loops
Intracellular loops
N -Terminal chain
HO2C
NH2
VII VI V IV III II IMembrane
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O O
Molecular Weight: 258.40
O O
ot ~ 0.001 ppb
ot ~ 0.44 ppb
ot ~ 0.00063 ppb
ot ~ 0.13 ppb
O
ot ~ 223 ppb
O
ot ~ 61 ppb
Molecular Weight: 238.41
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O
(S)-Carvone
O
(R)-Carvone
caraway spearmint
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Olfactory Receptorsand the
7!Transmembrane G!protein coupled receptor proteins "GCPR #
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ß
!
"
GDP GTP
Ligand
binding
Inducedfit
G-protein
binds
Induced
fit for
G-protein
ß
!
"
Ligand
Receptor
G Protein
Cell membrane
ß
!
"
Binding site for G-protein opens
= GDP
Interaction of receptor with G!protein
Guanosine diphosphate Guanosine triphosphate
The cAMP Transduction Cascade
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ß
!
"
Binding site recognizes GTP
GTP binds
Induced fit
G-protein alters !-subunit shape
Complex destabilized
Fragmentationand release
ß
!
"ß
!
"
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Interaction of !!subunit with adenylate cyclase
Active site"closed#
Binding site
for!!
subunit
cyclic AMPATP
Binding
Inducedfit
Active site"open #
!!subunit
Adenylate cyclase
GTPGDP
cAMP acts as hormone thatactivates Ca 2+ ion channels
Signal transduction via axons
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Summary
Sound Like ALOT to Remember?
ß
!
"
GDP GTP1. Odorant " ligand # binds receptor, which then binds G!protein
2. GDP leaves and GTP binds, resulting in destabilizing complex
3. !!Subunit binds adenylate cyclase where ATP is converted to cAMP
4. cAMP activates Ca2+ ion channels resulting in signal transduction
cyclic AMPATP
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Receptorcells
Olfactory bulb
Olfactory cortex
Hypothalamusemotion and memory
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Fragrance Perception
Humans use 350 ! 400 di$ erent types of olfactory receptors! variations among individuals
Statistically, each individual may detect odor with di$ erent combination of receptors
Odor ! Emotion, each individual response may depend on previous experiences
Market Research - understanding your customers
Sensory Analysis - using humans as measuring tool
Can you discriminate between odors?
Can you recognize odors (vocabulary)?
7/24/2019 Olfaction and Perception
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Sensory AnalysisOdor Threshold
O O
O
O
Floral!musk, 200 ppb " in water #
O
O
O
O Classical musky odor, 0.7 ng/L " in air #
O Powerful musk odor, 0.00063 ppb " in air #
1 ppb " part per billion # = 1 microgram/L = 0.000001 g/L = 0.0000001 %
1,000,000 microgram = 1 gram
1 ng = 0.000000001 g
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Sensory AnalysisOdor Threshold
O
H
(-) ambrox
ot ~ 1 ppb
O
O
OH
maltol
ot ~ 35,000 ppb
vp ~ 0.01 mm Hg @ 25 C vp = 0.0005 mm Hg @ 25 C
mp = 75 C mp = 162 C
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Sensory AnalysisOdor Profiling
Animal: Refers to the warm, sensual and heady base notes once associated with the natural odor of musk, ambergris, civet, andcastoreum, now produced by some vegetable materials and aroma chemicals.
Herbaceous: Aromatic and sharp, deriving from the plant kingdom, these are closely linked to the green notes, whilst at the same time taking on more complex characteristics. They are particularly
aromatic and in general have a scent similar to that of the earth, therefore grass and roots.
Amber: Rich, spicy, warm, sweet and sensual. Smooth, rich and intoxicating, amber is one of the hardest fragrances to describe.
Balsamic: Pungent, fresh. A heavy scent that calls to mind sticky sap. " balsamic vinegar, mint, pine #
Green: Penetrating and spontaneous, this derives above all from leaves, stalks or freshly cut grass.Lively and bubbly, it can be traced back to certain flowers such as Violet, or fruits, such as Watermelon.
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Sensory AnalysisOdor Profiling
Spicy: Lively or pungent notes such as clove oil, cinnamon; characteristic of notes of carnation, ginger, lavender or thechemical spicy notes of eugenol or isoeugenol.
Woody: An odor which is linked to the aroma of freshly cut, dry wood or fibrous root such as sandalwood or vetiver.
Musky: Intense and persistent, typically masculine. In most cases, the smell reminds us of wood, resin and earth.
Marine/Ozone: Lively and e$ ervescent, fresh and agreeable, these notes remind us of water, the sea and the ozone.
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Sensory AnalysisOdor Profiling
Pane llist: ________________________________________ Date : _______________________
Sample
ID Flo ral Fru ity Citr us Herba l Gree n Mint Marine Sweet Spicy Woo dy Fres h
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Sensory AnalysisOdor Profiling
0
5
10
15
20
Floral Fruity Citrus Herbal Mint Sweet Woody Fresh
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Sensory AnalysisOdor Profiling
O
raspberry ketoneHO
O
CO2Mehedione
O
Pharaone
A B C
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Sensory AnalysisOdor Profiling
Top note " 15!25%#
Middle note " 30!40%#
Base/bottom note " 45!55%#
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Sensory AnalysisOdor Profiling - Multidimensional scaling map