Pergamon Presa
Life Sciences Vol . 16, pp . 1499-1506 Printed in the U.S .A .
MINIREVIEW
DISORDERS
IN GLUTATHIONE METABOLISM Ernest Beutler
Division
of Medicine
City of Hope Medical 1500 E .
Center
Duarte Road
Duarte, California
91010
Structure and Function to play an
Glutathione appears of many tissues .
Indeed,
important role in
it has been alleged that life, itself,
would not be possible without glutathione (1), remains unproven .
Reduced glutathione
tripeptide, y-glutamyl-cysteyl (2)
and symposia
Its function structural
in
(3)
the sulfhydryl
containing enzymes
(Figure
important
is a
Comprehensive monographs in
recent years .
be related to two
the Y carboxyl
group of glutamic
The free sulfhydryl
group
role in maintaining sulfhydryl-
in the active state,
maintaining hemoglobin in
1)
group of the cysteine moiety,
and the amino group of cysteine .
probably plays an
that
glycine .
suggestion which
a
about GSH have been published
and the peptide bond between acid
(GSH)
living organisms appear to
features :
the economy
its
native,
and,
in the red cell,
soluble form .
The fact
the peptide bond between glutamine and cysteine involves the
y-carboxyl group makes glutathione resistant to hydrolysis usual
peptidases .
the y-glutamyl amino acid .
Its degradation depends upon
glutathione may play an kidney,
brain,
the transfer of
group from glutathione to a receptor,
This circumstance
and
by the
usually an
has led to the proposal
that
important role in amino acid transport in
possibly
in other tissues through the y 1499
1500
Diaorders in Glutathione Metabolism
Vol. 16, No . 10
Glutamis Acid NH 2 HOOCCHCH 2 CH2 CO
NH
Glycine
SCH2 CHCO t NHCH 2 COOH Cystei ne Fig .
1
The structure of reduced glutathione glutamyl
cycle, which has
been
(GSH)
described in detail
by Meister (4) .
Turnover Much of our knowledge of the physiology and pathophysiology of glutathione metabolism has been derived from studies of erythrocytes . glutathione, sequential
Red blood cells a synthesis which
have is
the capacity to synthesize
accomplished
through two
enzymatically catalyzed steps :
GC-S* glutamic acid + cysteine + ATP --+Y glutamyl y glutamyl Red cell half-life is
only
cysteine + ADP + Pi
GSH-Sf cysteine + glycine + ATP -~. GSH + ADP + P1
glutathione
appears to have an active turnover with a
of about 4 days partially
(5) .
understood .
The fate of red cell It has been found
glutathione
that red cells
have a transport system which actively extrudes oxidized glutathione
(GSSG)
from the erythrocytes
(6) .
A similar system has
been demonstrated to exist in porcine liver (7) .
It is not
certain what proportion of glutathione turnover can for by this system .
It has been proposed that turnover of GSH in
erythrocytes is due to operation of the y-glutamyl we have been
be accounted
unable to confirm
in erythrocytes
cycle,
but
the existence of
Vol. 16, No . 10
1501
Disorders in Glutathione Metabolism
y-glutamyl transpeptidase,
an activity which would be necessary
for operation of the cycle . Oxidation
and Reduction
It was
once believed that as much as
glutathione existed in that this was * y
glutamyl
30 or 40% of red cell
the oxidized farm (GSSG) .
We now recognize
due to the oxidation of GSH during analysis,
and that
cysteine synthetase
t glutathione synthetase the actual (8) .
ratio of oxidized to
Very high levels of GSSG can
of various enzymes It is
reduced GSH
unlikely,
(9,10)
exist
primarily through mediation Reduction
the enzyme,
(11) .
levels are achieved in vivo .
Oxidation
of the enzyme,
appears to occur
glutathione peroxidase
of GSSG to GSH occurs through mediation of
glutathione reductase
preferred, physiological,
(GR), with NADPH serving as the
hydrogen donor .
metabolism affecting synthesis, described although, as will significance
to inhibit the activity
for the oxidation of glutathione and
for the reduction of GSSG to GSH .
(GSH-Px) .
be shown
and to inhibit protein synthesis
however, that such
Enzymatic mechanisms
is only about 1 :400
Disorders of glutathione and reduction have been
oxidation,
be pointed out below,
of some of these "disorders"
the clinical
is uncertain .
Disorders
of GSSG transport and GSH degradation are unknown . Abnormalities of GSH Metabolism Genetically determined disorders of both steps of GSH synthesis, Y-glutamyl synthetase,
cysteine synthetase and glutathione
have been described
(12,13,14) .
These have been
associated with hemolytic anemia which is accelerated by the administration of "oxidant" drugs . amino acid levels in
the spinal
Amino aciduria and increased
fluid
have also been
found,
a
1502
Disorders in Glutathione Metabolism
Vol. 16, No . 10
finding consistent with the operation of the Y-glutamyl Increases in y-glutamyl
amino acid transport .
cycle
in
cysteine synthetase
activity occurs in some myeloproliferative disorders and after (15,16),
administration of certain drugs activity is
associated with an
This
increase in red
increase
in enzyme
cell
levels .
GSH
The most common disorders of glutathione metabolism involve the mechanisms for oxidation and
reduction
genase deficiency
system,
Since
for glutathione reductase,
NADPH serves as a hydrogen donor in the NADPH-generating
of glutathione .
viz,
defects
glucose-6-phosphate dehydro-
(17), result in impaired
glutathione reduction .
This can be demonstrated by incubating red cells with acetyl phenylhydrazine GSH disappears
(the
glutathione stability test
(18)) in which
from G-6-PD deficient but not from normal
It can also be demonstrated by rapidly oxidizing GSH cytes with azoester (1), peroxide
(19)
diamide
or tertiary butyl hydro-
regeneration
is slow,
enzyme deficiency occurs
is a
and most
However,
only very rarely if at all,
function of riboflavin nutrition in normal
containing)
and inactive (FAD lacking)
(20,21) .
red cells exists both
deficient erythrocytes
both
in
forms,
in humans and
reduction is
the active (FAD Studies
of GR-
in riboflavin-deficient reduced to
no impairment of the rate of glutathione
demonstrated
enzyme in GR reduction electrophoretic
erythrocytes
GR is a flavin
rats has indicated that even when enzyme activity is under one-half,
this
as a genetic
Most generally, the level of GR activity in
enzyme, and
well
In
does not occur at all .
Modest deficiency of GR is a common finding .
disorder,
in erythro-
and observing the rate of regeneration of GSH .
the case of G-6-PD deficiency, generally,
(1),
cells .
(22) :
apparently GR is not a limiting
until very low levels are achieved .
polymorphism involving GR
is known to occur
An (23),
150 3
Disorders in Glutathione Metabolism
Vol . 16, No . 10
and is reported to be statistically related
to blood-uric acid
levels, an association which is of very uncertain significance . Mild deficiency of the also common,
glutathione-oxidizing
GSH-Px is a selenium-containing enzyme (24,25),
and the activity of this dependent upon
GSH-Px are
importance of these disturbances
but the clinical
is not established .
enzyme,
enzyme in erythrocytes and other cells
the state of selenium nutrition
(26) .
is
Selenium
deficiency produces a severe induced glutathione peroxidase deficiency .
A mild deficiency of GSH-Px is also observed in
certain ethnic groups,
particularly both Ashkenazi
Jews and other persons
of Mediterranean origin
hemolytic states have been attributed to a (28),
a
Although
deficiency of GSH-Px
An electrophoretic polymorphism involving GSH-Px
has also been detected, polymorphism is
particularly among Afro-Americans
work was
National
(29) .
not associated with any alteration of GSH-Px
activity, and appears to have no clinical
This
(27) .
cause-and-effect relationship has not clearly been
established .
This
and Sephardic
consequences .
supported in part by Grant #HL07449
from the
Institutes of Health . REFERENCES
E .M .
KOSOWER and N .S .
P .C .
JOCELYN,
L.
FLÖHE, H .C .
Glutathione ,
BENÖf~R,
H.
SIES,
Academic Press,
A.
MEISTER, Science 180,
5.
E.
DIMANT, E .
H .D .
Inc .,
33-39
LANDBERG and
(1955) .
117-120
(1969) .
Academic Press,
(1972) .
4.
769-776
Nature 224,
Biochemistr ,~f- the SH Group,
London and New York, 3.
KOSOWER,
I .H .
WALLER and A .
New York
WENDEL,
(1974) .
(1973) . LONDON, J .
Biol .
Chem .
213,
1504
Diaorders in Glutathione Metabolism
Vol . 16, No . 10
6.
S . K . SRIVASTAVA and E . BEUTLER, J . Biol . Chem . 244, 9-16 (1969) .
7.
H . SIES, C . GERSTENECKER, K .H . SUMMER, H . MENZEL and L . FLÖHE, Glutathione (L . Flohe, H .C . Benôhr, H . Sies, H . D . Wallar and A . Wendel, ads .), pp . 261-216, Academic Press, New York (1974) .
8.
S . K . SRIVASTAVA and E . BEUTLER, Anal . Biochem . 25, 70-76 (1968) .
9.
E . BEUTLER and L . TEEPLE, Acta Biol . Med . Ger . 22, 707-711
10 .
(1969) .
D . SCHEUCH, C . KAHRIG, E . OCKEL, C . WAGENKNECHT and S . RAPOPORT, Nature 190, 631
(1961) .
11 .
N .S . KOSOWER and E .M . KOSOWER, Lancet 2, 1343-1344 (1970) .
12 .
P . BOIVIN, C . GALAND and J .F . BERNARD, Glutathione (L . Flohe, H .C . Benöhr, H . Sies, H . D . Wallar and A . Wendel, ads .) pp . 146-157, Academic Press, Inc ., New York (1974) .
13 .
D .N . MOHLER, P .W . MAJERUS, V . MINNICH, C .E . HESS and M .D . GARRICK, N . Engl . J . Med . 283, 1253-1257 (1970) .
14 .
P .N . KONRAD, F . RICHARDS II, W .N . VALENTINE and D .E . PAGLIA, N . Engl . J . Med . 286, 557-561 (1972) .
15 .
K . BLUME, N .V . PANIKER and E . BEUTLER, Clin . Chim . Acta 45, 281-285 (1973) .
16 .
N .V . 487
17 .
E.
PANIKER and E .
BEUTLER, J .
Lab .
Clin .
Med .
80,
481-
(1972) . BEUTLER,
(J .B . pp .
The Metabolic Basis of Inherited Disease,
Stanbury,
J .B .
Wyngaarden
1358-1388, McGraw-Hill,
and D .S .
Fredrickson,
ads .)
Inc ., New York, Third Edition
(1972) . 18 .
E.
BEUTLER,
J.
Lab .
19 .
S .K .
SRIVASTAVA,
139,
289-295
Clin .
Y .C .
Med .
49, 84-94 (1957) .
AWASTHI and E .
BEUTLER,
Biochem .
J.
24,
(1968) .
(1974) .
20 .
E.
BEUTLER,
Science 165, 613-615 (1969) .
21 .
D.
GLATZLE,
F.
WEBER and 0 .
WISS,
Experientia
1122
Vol. 16, No . 10
22 .
N .V .
Disorders in Glutathione Metabolism
PANIKER, S .K .
Biophys .
Acts,
SRIVASTAVA,
215,
23 .
W .K .
LONG, Science
24 .
S .I~ .
OH, H .E .
456-460 155,
and E .
BEUTLER,
1505
Biochim .
(1970) .
712-713
GANTHER and W .G .
(1967) . HOEKSTRA,
Biochemistry 13,
1825-1829 (1974) . 25 .
L.
FLORE and W .A .
Benôhr,
H.
Sies,
GUENZLER, Glutathione H .D .
Waller and A .
132-145, Academic Press, 26 .
P .J .
(L .
Flohe,
C .H .
Wendel,
eds .),
pp .
New York (1974) .
SMITH, A .L . TAPPEL and C .K .
CHOW, Nature 247,
392-393
(1974) . 27 .
28 .
29,
E.
BEUTLER,
925
(1974) .
F.
MATSUMOTO, C .
T .F . NECHELES, M .H . 19, 605-612
(1970) .
E.
C.
169
BEUTLER, (1974) .
WEST and E .
STEINBERG and D .
WEST and B .
GUINTO,
CAMERON,
BEUTLER, Ann .
Hum .
Br .
Blood 44,
J,
Genet,
Haematol .
38,
163-
Life Sciences Vol . 16, pp . 1499-1506 Printed in the U.S .A .
MINIREVIEW
DISORDERS
IN GLUTATHIONE METABOLISM Ernest Beutler
Division
of Medicine
City of Hope Medical 1500 E .
Center
Duarte Road
Duarte, California
91010
Structure and Function to play an
Glutathione appears of many tissues .
Indeed,
important role in
it has been alleged that life, itself,
would not be possible without glutathione (1), remains unproven .
Reduced glutathione
tripeptide, y-glutamyl-cysteyl (2)
and symposia
Its function structural
in
(3)
the sulfhydryl
containing enzymes
(Figure
important
is a
Comprehensive monographs in
recent years .
be related to two
the Y carboxyl
group of glutamic
The free sulfhydryl
group
role in maintaining sulfhydryl-
in the active state,
maintaining hemoglobin in
1)
group of the cysteine moiety,
and the amino group of cysteine .
probably plays an
that
glycine .
suggestion which
a
about GSH have been published
and the peptide bond between acid
(GSH)
living organisms appear to
features :
the economy
its
native,
and,
in the red cell,
soluble form .
The fact
the peptide bond between glutamine and cysteine involves the
y-carboxyl group makes glutathione resistant to hydrolysis usual
peptidases .
the y-glutamyl amino acid .
Its degradation depends upon
glutathione may play an kidney,
brain,
the transfer of
group from glutathione to a receptor,
This circumstance
and
by the
usually an
has led to the proposal
that
important role in amino acid transport in
possibly
in other tissues through the y 1499
1500
Diaorders in Glutathione Metabolism
Vol. 16, No . 10
Glutamis Acid NH 2 HOOCCHCH 2 CH2 CO
NH
Glycine
SCH2 CHCO t NHCH 2 COOH Cystei ne Fig .
1
The structure of reduced glutathione glutamyl
cycle, which has
been
(GSH)
described in detail
by Meister (4) .
Turnover Much of our knowledge of the physiology and pathophysiology of glutathione metabolism has been derived from studies of erythrocytes . glutathione, sequential
Red blood cells a synthesis which
have is
the capacity to synthesize
accomplished
through two
enzymatically catalyzed steps :
GC-S* glutamic acid + cysteine + ATP --+Y glutamyl y glutamyl Red cell half-life is
only
cysteine + ADP + Pi
GSH-Sf cysteine + glycine + ATP -~. GSH + ADP + P1
glutathione
appears to have an active turnover with a
of about 4 days partially
(5) .
understood .
The fate of red cell It has been found
glutathione
that red cells
have a transport system which actively extrudes oxidized glutathione
(GSSG)
from the erythrocytes
(6) .
A similar system has
been demonstrated to exist in porcine liver (7) .
It is not
certain what proportion of glutathione turnover can for by this system .
It has been proposed that turnover of GSH in
erythrocytes is due to operation of the y-glutamyl we have been
be accounted
unable to confirm
in erythrocytes
cycle,
but
the existence of
Vol. 16, No . 10
1501
Disorders in Glutathione Metabolism
y-glutamyl transpeptidase,
an activity which would be necessary
for operation of the cycle . Oxidation
and Reduction
It was
once believed that as much as
glutathione existed in that this was * y
glutamyl
30 or 40% of red cell
the oxidized farm (GSSG) .
We now recognize
due to the oxidation of GSH during analysis,
and that
cysteine synthetase
t glutathione synthetase the actual (8) .
ratio of oxidized to
Very high levels of GSSG can
of various enzymes It is
reduced GSH
unlikely,
(9,10)
exist
primarily through mediation Reduction
the enzyme,
(11) .
levels are achieved in vivo .
Oxidation
of the enzyme,
appears to occur
glutathione peroxidase
of GSSG to GSH occurs through mediation of
glutathione reductase
preferred, physiological,
(GR), with NADPH serving as the
hydrogen donor .
metabolism affecting synthesis, described although, as will significance
to inhibit the activity
for the oxidation of glutathione and
for the reduction of GSSG to GSH .
(GSH-Px) .
be shown
and to inhibit protein synthesis
however, that such
Enzymatic mechanisms
is only about 1 :400
Disorders of glutathione and reduction have been
oxidation,
be pointed out below,
of some of these "disorders"
the clinical
is uncertain .
Disorders
of GSSG transport and GSH degradation are unknown . Abnormalities of GSH Metabolism Genetically determined disorders of both steps of GSH synthesis, Y-glutamyl synthetase,
cysteine synthetase and glutathione
have been described
(12,13,14) .
These have been
associated with hemolytic anemia which is accelerated by the administration of "oxidant" drugs . amino acid levels in
the spinal
Amino aciduria and increased
fluid
have also been
found,
a
1502
Disorders in Glutathione Metabolism
Vol. 16, No . 10
finding consistent with the operation of the Y-glutamyl Increases in y-glutamyl
amino acid transport .
cycle
in
cysteine synthetase
activity occurs in some myeloproliferative disorders and after (15,16),
administration of certain drugs activity is
associated with an
This
increase in red
increase
in enzyme
cell
levels .
GSH
The most common disorders of glutathione metabolism involve the mechanisms for oxidation and
reduction
genase deficiency
system,
Since
for glutathione reductase,
NADPH serves as a hydrogen donor in the NADPH-generating
of glutathione .
viz,
defects
glucose-6-phosphate dehydro-
(17), result in impaired
glutathione reduction .
This can be demonstrated by incubating red cells with acetyl phenylhydrazine GSH disappears
(the
glutathione stability test
(18)) in which
from G-6-PD deficient but not from normal
It can also be demonstrated by rapidly oxidizing GSH cytes with azoester (1), peroxide
(19)
diamide
or tertiary butyl hydro-
regeneration
is slow,
enzyme deficiency occurs
is a
and most
However,
only very rarely if at all,
function of riboflavin nutrition in normal
containing)
and inactive (FAD lacking)
(20,21) .
red cells exists both
deficient erythrocytes
both
in
forms,
in humans and
reduction is
the active (FAD Studies
of GR-
in riboflavin-deficient reduced to
no impairment of the rate of glutathione
demonstrated
enzyme in GR reduction electrophoretic
erythrocytes
GR is a flavin
rats has indicated that even when enzyme activity is under one-half,
this
as a genetic
Most generally, the level of GR activity in
enzyme, and
well
In
does not occur at all .
Modest deficiency of GR is a common finding .
disorder,
in erythro-
and observing the rate of regeneration of GSH .
the case of G-6-PD deficiency, generally,
(1),
cells .
(22) :
apparently GR is not a limiting
until very low levels are achieved .
polymorphism involving GR
is known to occur
An (23),
150 3
Disorders in Glutathione Metabolism
Vol . 16, No . 10
and is reported to be statistically related
to blood-uric acid
levels, an association which is of very uncertain significance . Mild deficiency of the also common,
glutathione-oxidizing
GSH-Px is a selenium-containing enzyme (24,25),
and the activity of this dependent upon
GSH-Px are
importance of these disturbances
but the clinical
is not established .
enzyme,
enzyme in erythrocytes and other cells
the state of selenium nutrition
(26) .
is
Selenium
deficiency produces a severe induced glutathione peroxidase deficiency .
A mild deficiency of GSH-Px is also observed in
certain ethnic groups,
particularly both Ashkenazi
Jews and other persons
of Mediterranean origin
hemolytic states have been attributed to a (28),
a
Although
deficiency of GSH-Px
An electrophoretic polymorphism involving GSH-Px
has also been detected, polymorphism is
particularly among Afro-Americans
work was
National
(29) .
not associated with any alteration of GSH-Px
activity, and appears to have no clinical
This
(27) .
cause-and-effect relationship has not clearly been
established .
This
and Sephardic
consequences .
supported in part by Grant #HL07449
from the
Institutes of Health . REFERENCES
E .M .
KOSOWER and N .S .
P .C .
JOCELYN,
L.
FLÖHE, H .C .
Glutathione ,
BENÖf~R,
H.
SIES,
Academic Press,
A.
MEISTER, Science 180,
5.
E.
DIMANT, E .
H .D .
Inc .,
33-39
LANDBERG and
(1955) .
117-120
(1969) .
Academic Press,
(1972) .
4.
769-776
Nature 224,
Biochemistr ,~f- the SH Group,
London and New York, 3.
KOSOWER,
I .H .
WALLER and A .
New York
WENDEL,
(1974) .
(1973) . LONDON, J .
Biol .
Chem .
213,
1504
Diaorders in Glutathione Metabolism
Vol . 16, No . 10
6.
S . K . SRIVASTAVA and E . BEUTLER, J . Biol . Chem . 244, 9-16 (1969) .
7.
H . SIES, C . GERSTENECKER, K .H . SUMMER, H . MENZEL and L . FLÖHE, Glutathione (L . Flohe, H .C . Benôhr, H . Sies, H . D . Wallar and A . Wendel, ads .), pp . 261-216, Academic Press, New York (1974) .
8.
S . K . SRIVASTAVA and E . BEUTLER, Anal . Biochem . 25, 70-76 (1968) .
9.
E . BEUTLER and L . TEEPLE, Acta Biol . Med . Ger . 22, 707-711
10 .
(1969) .
D . SCHEUCH, C . KAHRIG, E . OCKEL, C . WAGENKNECHT and S . RAPOPORT, Nature 190, 631
(1961) .
11 .
N .S . KOSOWER and E .M . KOSOWER, Lancet 2, 1343-1344 (1970) .
12 .
P . BOIVIN, C . GALAND and J .F . BERNARD, Glutathione (L . Flohe, H .C . Benöhr, H . Sies, H . D . Wallar and A . Wendel, ads .) pp . 146-157, Academic Press, Inc ., New York (1974) .
13 .
D .N . MOHLER, P .W . MAJERUS, V . MINNICH, C .E . HESS and M .D . GARRICK, N . Engl . J . Med . 283, 1253-1257 (1970) .
14 .
P .N . KONRAD, F . RICHARDS II, W .N . VALENTINE and D .E . PAGLIA, N . Engl . J . Med . 286, 557-561 (1972) .
15 .
K . BLUME, N .V . PANIKER and E . BEUTLER, Clin . Chim . Acta 45, 281-285 (1973) .
16 .
N .V . 487
17 .
E.
PANIKER and E .
BEUTLER, J .
Lab .
Clin .
Med .
80,
481-
(1972) . BEUTLER,
(J .B . pp .
The Metabolic Basis of Inherited Disease,
Stanbury,
J .B .
Wyngaarden
1358-1388, McGraw-Hill,
and D .S .
Fredrickson,
ads .)
Inc ., New York, Third Edition
(1972) . 18 .
E.
BEUTLER,
J.
Lab .
19 .
S .K .
SRIVASTAVA,
139,
289-295
Clin .
Y .C .
Med .
49, 84-94 (1957) .
AWASTHI and E .
BEUTLER,
Biochem .
J.
24,
(1968) .
(1974) .
20 .
E.
BEUTLER,
Science 165, 613-615 (1969) .
21 .
D.
GLATZLE,
F.
WEBER and 0 .
WISS,
Experientia
1122
Vol. 16, No . 10
22 .
N .V .
Disorders in Glutathione Metabolism
PANIKER, S .K .
Biophys .
Acts,
SRIVASTAVA,
215,
23 .
W .K .
LONG, Science
24 .
S .I~ .
OH, H .E .
456-460 155,
and E .
BEUTLER,
1505
Biochim .
(1970) .
712-713
GANTHER and W .G .
(1967) . HOEKSTRA,
Biochemistry 13,
1825-1829 (1974) . 25 .
L.
FLORE and W .A .
Benôhr,
H.
Sies,
GUENZLER, Glutathione H .D .
Waller and A .
132-145, Academic Press, 26 .
P .J .
(L .
Flohe,
C .H .
Wendel,
eds .),
pp .
New York (1974) .
SMITH, A .L . TAPPEL and C .K .
CHOW, Nature 247,
392-393
(1974) . 27 .
28 .
29,
E.
BEUTLER,
925
(1974) .
F.
MATSUMOTO, C .
T .F . NECHELES, M .H . 19, 605-612
(1970) .
E.
C.
169
BEUTLER, (1974) .
WEST and E .
STEINBERG and D .
WEST and B .
GUINTO,
CAMERON,
BEUTLER, Ann .
Hum .
Br .
Blood 44,
J,
Genet,
Haematol .
38,
163-
