glycolysis biochemistry, 4 th edition, rh garrett & cm grisham,
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Glycolysis Biochemistry, 4 th edition, RH Garrett & CM Grisham, Brooks/Cole ( Cengage ); Boston, MA: 2010 pp 535-562 Instructor: Kirill Popov. General metabolism of glucose The reactions of glycolysis Metabolism of hexoses other than glucose Control of metabolic flux. - PowerPoint PPT PresentationTRANSCRIPT
GlycolysisBiochemistry, 4th edition, RH Garrett & CM Grisham, Brooks/Cole (Cengage); Boston, MA: 2010
pp 535-562
Instructor: Kirill Popov
1. General metabolism of glucose
2. The reactions of glycolysis
3. Metabolism of hexoses other than glucose
4. Control of metabolic flux
Glycogenolysis
Glycogen Triglyceride Protein
Acetyl-CoA
Amino acidsGlucose Free fatty acidsLipolysis Proteolysis
β-OxidationPyruvate Deamination and
oxidationOxidation
Glycolysis
Fate of major metabolic fuels
Glycogen
Glucose
Ribose 5-phosphate Pyruvate
oxidation viapentose phosphate
pathway
storage
oxidation viaglycolysis
Major metabolic pathways of glucose
Glucose
2 Pyruvate
2 Ethanol + 2 CO22 Lactate
2 Acetyl-CoA
4 CO2 + 4 H2O
glycolysis(10 successivereactions)
Fermentation tolactate in vigorouslycontracting muscle,erythrocytes, someother cells, and insome microorganisms
anaerobicsconditions
anaerobicsconditions
anaerobicsconditions
Fermentation to alcoholin yeast
citricacidcycle
Animal, plant, andmany microbial cellsunder aerobic conditions
2CO2
Catabolic fates of the pyruvate formed in glycolysis
D-Glucose 2 pyruvate 2 acetyl-CoAglycolysis PDH
2CO2 4CO22 L-lactate
No O2 requirementfor glycolysis
O2 requirement for pyruvatedehydrogenase (PDH) plus
TCA cycle activity
TCA
Glycolysis is a preparatory pathway for aerobic metabolism of glucose
Glucose
GlucosetransporterPlasma
membrane
[Glucose] mM
J glu
cose
(mM
îcm
îs-1
î106
)
Mechanism of glucose uptake
Major ways in which glucose is metabolized in different tissues
erythrocytes brain
muscle liver
Glucose
Glucose 6-phosphate
e-
Pentosephosphates
(2)Lactate-
(2) H+
Glucose
Glucose 6-phosphate
e-
Pentosephosphates
(2)Lactate-
(2) H+
(2) CO2
2 Acetyl-CoA(2) CO2
TCA
Glucose
Glucose 6-P
e-
Pentosephosphates
(2) H+
(2) CO2
2 Acetyl-CoA(2) CO2
TCA
(2)Lactate-(2)Pyruvate-
Glycogen?
Glucose
Glucose
e-
Pentosephosphates
(2) H+
(2) CO2
2 Acetyl-CoA(2) CO2
TCA
(2)Lactate-(2)Pyruvate-
Fat
Glucurinides
Glucose 6-P Glycogen
O CH2 C CH2 OH
O
P
O
CH2
OH
OH
OHOH
HO
C CO
O-O
CH3
second ATP-forming reaction(substrate-levelphosphorylation)
Glucose
Glucose 6-phosphate
Fructose 6-phosphate
Fructose 1,6-bisphosphate
Glyceraldehyde 3-phosphate
Dihydroxyacetone phosphate
Glyceraldehyde 3-phosphate (2)
1,3-Bisphosphoglycerate (2)
3-Phosphoglycerate (2)
2-Phosphoglycerate (2)
Phosphoenol pyruvate (2)
Pyruvate (2)
1
2
3
4
5
6
7
8
9
10
ATP
2 ATP
ADP
ATP
2ADP
2ADP
2 ATP
ADP
2 NADH + H+
2Pi2NAD+
firstpriming reaction
secondpriming reaction
cleavageof 6-carbonsugarphosphate totwo 3-carbonsugarphosphates
oxidation andphosphorylation
first ATP-forming reaction(substrate-levelphosphorylation)
Preparatory phasePhosphorylation of glucoseand its conversion toglyceraldehyde 3-phosphate
Payoff phaseOxidative conversion ofglyceraldehyde 3-phosphate topyruvate and the coupledformation of ATP and NADH
1
2
3
4
5
Hexokinase
Phosphohexoseisomerase
Phospho-fructokinase-1Aldolase
Triosephosphateisomerase
6
7
8
9
10
Glyceraldehyde 3-phosphatedehydrogenase
Phosphoglyceratekinase
Phosphoglyceratemutase
EnolasePyruvatekinase
O CH2 CH CO
HOH
P
O CH2 CH CO
HOH
P
CH2 C CO
O-O
P
OCH2
OH
OH
CH2 OHOP
OCH2
OH
OH
CH2 OO PP
O
CH2
OH
OH
OHOH
OP
O CH2 CH CO
O-OH
P
O CH2 CH CO
OOH P
P
CH2 CH CO
O-OH O
P
O
CH2
OH
OH
OHOH
HO
O
CH2
OH
OH
OHOH
OP-O
O-
O
hexokinase
ΔG'º = -16.7 kJ/mol
ATP ADP
Glucose Glucose 6-phosphate
Mg2+
1
23
4
5
6
Phosphorylation of glucose
O
CH2
OH
OH
OHOH
OP-O
O-
O
Glucose 6-phosphate
1
23
4
5
6
phosphohexoseisomerase
Mg2+
OP-O
O-
O
OCH2
OH
OH
CH2 OH
Fructose 6-phosphate
ΔG'º = 1.7 kJ/mol
1
2
34
5
6
Conversion of glucose 6-phosphate to fructose 6-phosphate
OP-O
O-
O
OCH2
OH
OH
CH2 O P
O
O-
O-
OP-O
O-
O
OCH2
OH
OH
CH2 OH
Fructose 6-phosphate
ΔG'º = -14.2 kJ/mol
1
2
34
5
6ATP ADP
Mg2+
phosphofructokinase-1
Fructose 1,6-bisphosphate
1
2
34
5
6
Phosphorylation of fructose 6-phosphate to fructose 1,6-bisphosphate
OP-O
O-
O
OCH2
OH
OH
CH2 O P
O
O-
O-
ΔG'º = 23.8 kJ/mol
Fructose 1,6-bisphosphate
1
2
34
5
6
aldolase
Glyceraldehyde3-phosphate
Dihydroxyacetonephosphate
CH2
C
CH2OH
O
O
P O-
O-
O
+
C
COH
CH2 O
HO
P O-
O-
OH
Cleavage of fructose 1,6-bisphosphate
ΔG'º = 7.5 kJ/mol
triose phosphateisomerase
Glyceraldehyde3-phosphate
Dihydroxyacetonephosphate
CH2OH
C
CH2 O P O-
O-
OO H
C
COH
CH2 O
HO
P O-
O-
O
Interconversion of the triose phosphates
HO P O-
O-
O P O-
O-
O
C
COH
CH2OPO32-
OO
ΔG'º = 6.3 kJ/mol
glyceraldehyde3-phosphate
dehydrogenase
Glyceraldehyde3-phosphate
Inorganicphosphate 1,3-Bisphosphoglycerate
NAD+ NADH + H+C
COH
CH2OPO32-
HO
H
Oxidation of glyceraldehyde 3-phosphate to 1,3 bisphosphoglycerate
C
C
CH2OPO32-
H
H
OH
O
C
C
CH2OPO32-
H
H
OH
OH
S
C
C
CH2OPO32-
H OH
S
O C
C
CH2OPO32-
H OH
S
O
C
C
CH2OPO32-
H OH
O
P-O
O
O
O-
OHP-O
O-
O
Glyceraldehyde 3-phosphatedehydrogenase
NAD+ NADH + H+
NADHNAD+ NAD+
SH
Thiohemiacetal Thioester
H+
Glyceraldehyde3-phosphate
1,3-Bisphospho-glycerate
Cys Cys Cys
Cys
NAD+
1 2 3 4
The glyceraldehyde 3-phosphate dehydrogenase reaction
ΔG'º = -18.5 kJ/mol
1,3-Bisphosphoglycerate
P O-
O-
O
C
COH
CH2OPO32-
OO C
COH
CH2OPO32-
O-O-O P O
O-
ADP ATP
phosphoglyceratekinase
3-Phosphoglycerate
AdenineRib
P
P
O
AdenineRib
P
P
O
+ +Mg2+
Phosphoryl transfer from 1,3-bisphosphoglycerate to ADP
ΔG'º = 4.4 kJ/mol
3-Phosphoglycerate
phosphoglyceratemutase
Mg2+C
C
CH2
O-O
O P O-
O-
OOHH
2-Phosphoglycerate
O
H O P O-
O-
OC
C
CH2
O-
OH
Conversion of 3-phosphoglycerate to 2-phosphoglycerate
3-Phosphoglycerate 2-Phosphoglyceratephosphoglyceratemutase
2,3-Bisphos-phoglycerate
Phosphoenzyme
3-Phosphoglycerate
3-Phosphoglycerate
2,3-Bisphosphoglycerateinitial phosphorylation
of enzyme
ADP ATP
Enzyme withunphosphorylatedHis residue
-O P O
O-
1 2
kinase
His
His
His
Mechanism of the phosphoglycerate mutase reaction
O P O-
O-
OC
C
CH2
O-O
HO
H O P O-
O-
OC
C
CH2
O-O
ΔG'º = 7.5 kJ/mol
enolase
Phosphoenolpyruvate2-Phosphoglycerate
H2O
Dehydration of 2-phosphoglycerate to phosphoenolpyruvate
O P O-
O-
OC
C
CH2
O-O
O
C
C
CH3
O-O-O P O
O-
ΔG'º = -31.4 kJ/mol
ADP
ATP
Pyruvate
Mg2+, K+
Phosphoenolpyruvate
pyruvatekinase
AdenineRib
P
P
OAdenineRib
P
P
O+ +
Transfer of the phosphoryl group from phosphoenolpyruvate to ADP
Glucose
2 Pyruvate 2 Lactate2 NADH
2 NAD+
Pyruvate is the terminal electron acceptor in lactic acid fermentation
O
C
C
CH3
O-O
H
C
C
CH3
O-O
HO
Pyruvate
Lactate
lactatedehydrogenase
ΔG'º = -25.1 kJ/mol
NADH + H+
NAD+
Lactate dehydrogenase reaction
O
CH2OH
OH
OH
OHOH
O
CH2OH
OH
OH
OH
OH
O
CH2OH
OH OHOHOH
OCH2OH
OH
OH
CH2OH
fructose 1-phosphatealdolase
LactoseTrehalose
Sucrose
Glycogen; starch
Glucose1-phosphate
Glucose6-phosphate
Fructose6-phosphate
Fructose 1,6-bisphosphate
Glyceraldehyde3-phosphate
Glyceraldehyde Dihydroxyacetonephosphate
D-Fructose
Mannose 6-phosphate
D-Mannose
D-Galactose
D-Glucose
Pi
ATP
ATP
ATP
UDP-glucose
UDP-galactose
Fructose 1-phosphate
ATP
hexokinase
hexokinase
sucrase
trehalase lactase
hexokinaseATP
phosphorylase
phosphogluco-mutase
fructokinasePhosphomannose
isomerase
triosekinase
triose phosphateisomerase
+
Entry of dietary hexoses into the preparatory stage of glycolysis
½ Glucose
1,3-Bisphosphoglycerate
3-Phosphoglycerate
2-Phosphoglycerate
Lactate
2,3-BisphosphoglycerateATP
ADP
The 2,3bisphosphoglycerate shunt
Glucose
Glucosetransporter
EndocytosisExocytosis
Stimulationby insulin
Membranousvesicle
Plasma membrane
Insulin stimulates glucose uptake by adipose tissue and muscle
Glucose concentration (mM)
Rel
ativ
e en
zym
e ac
tivity
20
1.0
151050
Kinetic properties of glucokinase and hexokinase
Capillary
Glucose
GLUT2
Glucose
Fructose 6-phosphate
Glucose 6-phosphate
Cytosol Nucleus
Hexokinase IV
Regulatorprotein
Plasmamembrain
Hexokinase IV
Regulation of glucokinase by sequestration in the nucleus
Fructose 6- + ATPphosphate
Fructose 1,6- + ADPphosphate
ATP AMP, ADP
citrate fructose 2,6-bisphosphate
Regulation of phosphofructokinase-1
Relative Changes in [ATP] and [AMP] When ATP Is Consumed
Adenine nucleotide
Concentration before ATP
depletion (mM)
Concentration after ATP depletion (mM)
Relative change
ATP 5.0 4.5 10%ADP 1.0 1.0 0AMP 0.1 0.6 600%
Fructose 6-phosphate
PFK
-1 a
ctiv
ityLow [ATP]
High [ATP]
Regulation of phosphofructokinase-1
O
O
H
OH
OH
O
H
C H2 POP O -
O -
-O
O -
OO
HCH 2OH1
2
34
5
6
Fructose 2,6-bisphosphate
[Fructose 6-phosphate] (mM)
PFK
-1 a
ctiv
ity (%
of V
max
)
-F2,6BP
+F2,6BP
100
80
60
40
20
00 0.05 0.1 0.2 0.4 0.7 1.0 2.0 4.0
Role of fructose 2,6-bisphosphate in regulation of PFK-1
All glycolytic tissues, including liverLiver only
transamination
glucagon
ATPADP
Pyruvatekinase L(inactive)
Pyruvatekinase
L/M
PEP
F16BP
ADP
ATP
Pyruvate
Alanine
ATP,acetyl-CoA,long-chainfatty acids
6 steps
PKA
PP
PiH2O
P
Regulation of pyruvate kinase
Glucose
(2) Pi
Glucose 6-phosphate
Fructose 6-phosphate
Fructose 1,6-bisphosphate
(2) Glyceraldehyde 3-phosphate
(2) 1,3-Bisphosphoglycerate
(2) Phosphoenolpyruvate
(2) Pyruvate
(2) Lactate
Glycogensynthesis
Pentosephosphate pathway
ATP
ATP
(2) ADP(2) ATP
ADP
ADP
AMP, Fructose 2,6-P2ATP, citrate, H+
ATP, alanine
(2) NAD+
(2) NADH + 2H+
(2) NADH + 2H+
(2) NAD+
++
++
−
Important regulatory features of glycolytic pathway
1. Glycolysis is a near universal pathway by which a glucose molecule is oxidized to two molecules of pyruvate, with energy conserved as ATP and NADH
2. All ten glycolytic enzymes are in cytosol, and all the intermediates are phosphorylated compounds of three or six carbons
3. In the preparatory phase of glycolysis, ATP is invested to convert glucose to fructose 1,6-bisphosphate; fructose 1,6-bisphosphate is than broken to yield two molecules of triose phosphate
4. In the payoff phase, each of the two molecules of glyceraldehyde 3-phosphate undergoes oxidation; the energy of this oxidation is conserved in the formation of NADH and ATP
5. Glycolysis is tightly regulated in coordination with other energy-yielding pathways