Vol. 73, No. 1, 1976
ACTION
BIOCHEMICAL
OF PROTEINASES
OF PURIFIED
ON THE
VACUOLES
M. Diirr,
Swiss
Federal
Institute
September
ARGININE
RESEARCH COMMUNICATIONS
TRANSPORT
FROM SACCHAROMYCES
Th.
Boiler
of Technology
Sonneggstrasse Received
AND BfOPHYSlCAL
SYSTEM
CEREVISIAE.
and A. Wiemken
Ziirich,
5, CH-8092
Department Ziirich,
of General
Botany,
Switzerland
14,1976
Thermolysin, a commercial bacterial proteinase, greatly activated the arginine transport system of isolated yeast vacuoles. Pronase had the same effect at low concentrations, but rapidly inactivated the transport system at higher concentrations. Arginine specifically protected the transport system The protective effect of other amino acids form the inactivation by pronase. correlated well with their affinity for the transport system. It is concluded that both thermolysin and pronase attack a membrane protein which restrains the transport of arginine, whereas the protein which carries the specific binding site of this transport system can be destroyed only by pronase.
summary:
Vacuoles
isolated
active
transport
system
is mediated
of proteinases. Saccharide attack
system
Material
Preparation
for
which, (2),
of the vacuoles
spheroplasts
arginine
We considered residues
and
yeast
by a membrane
of proteases
surface
from
(1).
protein
vacuoles it
is
The question
suitable
for
protect
shown to be absent
contain
whether
can be examined
suspected,
have been
and purified
this
by studying
a highly transport the effect
such an experiment: the membrane from
from
the outer
the membrane
(3).
Methods:
of yeast
spheroplasts
and vacuoles
Spheroplasts were obtained from growing cultures of Saccharomyces cerevisiae (strain LBG H 1022, Institute for Microbiology, ETH, Ziirich). The spheroplasts were disrupted under isotonic conditions (0.6 M sorbitol containing 5 mM TrisPipes, pH 6.8 [TP-buffer])8by polybase-induced lysis as described (4) using 100 ug DEAE-dextran per 10 spheroplasts. The vacuoles were separated from the homogenate as described (4) but the method was scaled up by using a zonal rotor (type Beckman Ti-14). The homogenate was layered on a gradient 193 Copyrighr All rights
0 1976 by Academic Press, of reproduction in an>> form
Inc. reserved.
Vol. 73, No. 1,1976
BIOCHEMICAL
AND BIOPHYSICAL RESEARCH COMMUNICATIONS
consisting of two washing layers (0.5 M sorbitol with 0.1 M sucrose, 100 ml, and 0.45 M sorbitol with 0.15 M sucrose, 100 ml, respectively) and a reception layer (0.6 M sucrose, 100 ml) on top of which the vacuoles float after centrifugation. All solutions were buffered with TP-buffer. After 30 min centrifugation at 100'000 x g, the gradient was displaced by 30 % sucrose and the fractions containing the vacuoles were combined. They were mixed with 4 volumes of 0.6 M sorbitol and the vacuoles sedimentated by 30 min centrifugation at 2'000 x g. The purified vacuoles were resuspended in 0.6 M sorbitol with TP-buffer, at a final concentration of 5 x 107 vacuoles per ml. Protease
treatment
of the vacuoles
and assay
for
arginine
transport
1 ml portions of purified vacuoles were preincubated for 5 min at 25' C and then mixed with 50 ~1 of protease solution prepared with 0.6 M sorbitol containing TP-buffer and 10 mM CaC12. After specified intervals the vacuoles were separated from the proteases by centrifugation through a discontinuous isotonic density gradient (1). The vacuoles were taken up in 0.6 M sorbitol with TP-buffer, and the initial rate of the transport of 100 IJM L-E3H]arginine was determined as described (1). Chemicals
and protease
preparations
L-[3H]arginine was obtained from New England Nuclear, Boston, USA. Pronase was purchased from Koch-Light, Colnbrook Bucks, England, and Thermolysin (Protease type X) from Sigma, St.Louis, USA. One protealytic unit* was defined as the amount of protease which liberates 1 ~01 acid soluble tyrosine per min from 1 % casein under the conditions used for the pgotease treatment of the vacuoles (0.6 M sorbitol; TP-buffer; 0.5 M CaC12; 25 C). Results
and Discussion
Activation
of vacuolar
The effect
of incubation
preparation first
consisting
tested.
transport
and ranged
experiments. transport
It in the
Apparently As compared acids
were
sedimentated * Abbreviation:
with
The maximal
for
the untreated
has been
found
1 proteolytic
thermolysin,
-depending with
activity
a bacterial
proteolytic
thermolysin
protease
enzyme, activated
was attained
the vacuoles
control
after
was
their 10 min with
1U
in different
with
a low absolute
rate
of
upon
treatment
thermoysin.
controls.
of vacuoles
in the
2+
170 to 600 % of the
untreated
recovered
Ca
of vacuoles
from
by thermolysin
with
of a single
was higher
a fraction
transport
of vacuoles
The treatment
of arginine.
thermolysin
arginine
was lysed only
controls, sediment.
The amount
to be a reliable unit
about
= 1 U
194
with
70 % of the vacuolar
of vacuolar
measure
for
amino
the amount
amino
acids of intact
Vol. 73, No. 1, 1976
BIOCHEMICAL
AND BIOPHYSICAL
RESEARCH COMMUNICATIONS
control
z
5 Perlad
1: Thermolysin
I
0 0
Fig.
.
lOU/ml+O5mM EDTA
c1. z @J 10
of mcubatmn
activates
15
wth
thermolysln
the vacuolar
20 lm~ni
transport
system
5 x lo7 vacuoles per ml were incubated with 50 ul of thermolysin (1.0 or 0.2 U) preincubated either with 10 mM CaC12 or 10 mM Tris-EDTA. At the time indicated the vacuoles were separated from the incubation mixture by centrifugation through discontinuous density gradients, resuspended in 0.6 M sorbitol with 5 mM Tris-Pipes, pH 6.8, and assayed for the initial transport rate of 100 UM L-[3H]arginine.
vacuoles calculation Under
and therefore
served
of the transport
rate.
(l),
the assay
activity
conditions
This
indicates
against
The increase either
the
in transport
as a proteolytic
dissection
effect
Pronase,
a protease
a high
potency
3.3 mU pronase
per
apparent.
which
native
of the
2).
However,
(Fig.
proteolytic
arginine
followed
1).
action.
can be explained carrier
proteolytic
inactivation
195
of
sites
or as a
of the carrier.
transport
when higher
activity
system
the mobility
was next
activated
a concomitant transport
hidden
several
proteins,
5 x lo7 vacuoles (Fig.
transport
by thermolysin
containing
the
the proteolytic
is due to its
arginine
for
in the presence
arginine
restrains
on vacuolar
(15 - 67 mu), The decay
induced
protein
to degrade
inhibited
of preexisting
preparation
same way as thermolysin applied
activity
of pronase
on the
of thermolysin
liberation
of a membrane
The dual
were
effect
of reference
Correspondingly
casein.
had no effect
that
as a basis
0.5 mM EDTA completely
of thermolysin
0.5mM EDTA thermolysin
always
examined.
enzymes with A ratio
transport pronase of the first
of
in the concentrations system order
became kinetics
Vol. 73, No. 1, 1976
BIOCHEMICAL
AND BIOPHYSICAL
RESEARCH COMMUNICATIONS
/.E Etj;15 0F
P “s 1 P
50 30 20 0
5 Period
Fig.
2: Effect of various transport Fig.
As
1, but
10
pronase
thermolysin
15
of incubation
by 3.3,
.
Fig.
3: Protection inactivation
taken
the
first
0.7 min -1 for A possible fact
7 min if
as the value
that
resuspension
arginine
15, 27, 67 mU of pronase.
Arg .
10
of incubation
with pronase
Iminl
of the arginine transport system from proteolytic by its substrates, arginine and lysine
As Fig. 2, but with before the addition
over
on vacuolar
67mU/ml+2.5m.M
5 Period
Iminl
concentrations
replaced
0
20
with pronase
for
addition of 10 ~1 0.2 M L-arginine of pronase.
the maximally zero
time.
activatedtransport
The decay
15 mU and 67 mU pronase,
explanation some vacuoles and transport
for were
the
slowed
destroyed assays,
or L-lysine
rate
constants
were
0.14
1 min
(260 %> was min -1 and
respectively. decay
after
the
by the pronase
30 % less
196
vacuoles
first
7 min lies
treatment: were
in the
After
sedimentated
than
BIOCHEMICAL
Vol. 73, No. 1,1976
in the
controls
arginine
pool
system
of the
Substrate
for
remaining
vacuoles,
acids
of more than
the destroyed
protect
RESEARCH COMMUNICATIONS
vacuoles
as demonstrated
the vacuolar
7 min.
may protect
The internal the
transport
below.
arginine
transport
system
activated
the
from
inactivation
transport
system
is not
identical
Tab.
incubations
from
In the presence
This
pronase
liberated
amino
proteolytic
all
AND BIOPHYSICAL
of 2.5 mM L-arginine, (Fig.
3) but
no longer
due to an inhibition in the
absence
pronase
displayed
of pronase
or presence
L: Effect of different amino the proteolytic inactivation
still
as its
the
subsequent
activity
against
arginine inactivation. casein
was
of 2.5 mM arginine.
acids on the transport of L-arginine of the arginine transport system
and on
The transport rate of vacuoles for 100 PM L-[3H]arginine was determined in the presence of the amino acids listed. Vacuoles of the same batch were used for studying the effect of the amino acids on the kinetic of proteolytic 7 inactivation of the arginine transport system. 5 x 10 vacuoles in 1 ml were incubated for 2, 5, 10 and 20 min with 50 ~1 pronase (67 mU) in the presence of 0.5 mM CaC12and the amino acids listed. The vacuoles were then separated from the incubation mixture by centrifugation through discontinuous density gradients, resuspended, and their initial rate of arginine transport determined. From plots as shown in Fig. 3 for arginine and lysine, the rate constants of the proteolytic inactivation of the arginine transport system were estimated. Amino
acid
Cont.
mM
Transport rate of 100 uM L-[3H]arginine
Rate constant of the proteolytic inactivation of the arginine carrier
pmoles per nmol amino acid per min
%
min
-1
%
7.7
100
0.56
100
L-leucine
2
6.7
87
0.56
100
Glysine
2
3.4
44
0.26
46
L-histidine
2
2.2
29
0.19
34
D-atginine
2
1.0
13
0.075
13
L-arginine
0.5
1.3
17
0.12
21
L-arginine
2
0.6
8
0.00
0
197
Vol. 73, No. 1,1976
BIOCHEMICAL
The presence
of 2.5 mM L-lysine,
the vacuolar
arginine
only
by ca.
In the experiment amino
acids
measuring
for their
respective
amino arginine
ability
attribute
transport
site
arginine
for
However,
this
unoccupied
spheroplasts
to bind
the present vacuolar vacuole
for
of the system
of a number
were
established
The ability
of
by
of the
of the arginine
of vacuoles.
proteolytic
For
each of the
inactivation
of the
to the respective
affinity
for
transport
attack
have
acid
the same cause;
to the
specific
the protein system
by pronase
arginine
site
carrying
is destroyed
occurs
transport
of intact
Possibly
membrane
only
if
we of the
the specific by pronase.
the
site
is
(3)
of spheroplasts
spheroplasts
(1)
of pronase the
(up to 1200 mU per
saccharide
protect
was found
residues
the transport
covering system
to be 5 x lo7 the
outer
of the
by pronase.
this A are
susceptibility
connection distributed of which is
exposed
was found
effects
that
concentrations
attack in
both
molecule.
communication,
(G),
same batch
closely
that
of the
system
plasma
membrane,
of decay
inactivation
of the amino
on the
Concanavalin the
the
and conclude
10 min).
from
system transport.
to inhibit
of the
to high
interesting
surface,
with
suggest
transport
of the
affinity
system.
system
for
a poor
affinities
transport
corresponded
binding
even
with
the rate
proteolytic
ability
system
has no effect
spheroplasts
is
the
by a substrate
resistant
It
was tested
effect
The arginine
reduced
arginine
to inhibit
to the binding
arginine
surface
acids
strongly
this
acid
1, the relative
to inhibit
transport
findings
Pronase
arginine
transport
the arginine These
the vacuolar
tested,
amino
RESEARCH COMMUNICATIONS
3). in Tab.
system acids
system
presented
amino
transport
a basic
transport
70 % (Fig.
AND BIOPHYSICAL
free
to several
to be covered
to consider
how saccharide
on the vacuolar to pronase of them. potent with 198
membrane
and thermolysin
However proteases saccharide
the
residues
able
(3).
outer
we examined
inner
surface
located
within
residues.
Its
of the the
in
Vol. 73, No. 1, 1976
BIOCHEMICAL
AND BIOPHYSICAL
RESEARCH COMMUNICATIONS
Acknowledgements: We like to express our sincere thanks to B. Coombe, Ph. Matile and S. Turler for their help in preparing the manuscript. This was supported by the Swiss National Science Foundation.
work
References: 1. Boller, Th., Diirr, M., and Wiemken, A. (1975) Eur. J. Biochem. lft, 81-91. R. (1972) J. Biol. Chem. 247, 2. Kahlenberg, A., Dolansky, D., and Rohrlick, 4572-4576. 3. Boller, Th., Diirr, M., and Wiemken, A. (1976) Arch. Microbial. 109, 115-118. 4. Diirr, M., Boller, Th., and Wiemken, A. (1975) Arch. Microbial. 105, 319-327. 101, 45-57. 5. Wiemken, A., and Diirr, M. (1974) Arch. Microbial. 6. Lenney, J.F., Matile, Ph., Wiemken, A., Schellenberg, M., and Meyer, J. (1974) Biochem. Biophys. Res. Cormnun. 60, 13781383.
199
ACTION
BIOCHEMICAL
OF PROTEINASES
OF PURIFIED
ON THE
VACUOLES
M. Diirr,
Swiss
Federal
Institute
September
ARGININE
RESEARCH COMMUNICATIONS
TRANSPORT
FROM SACCHAROMYCES
Th.
Boiler
of Technology
Sonneggstrasse Received
AND BfOPHYSlCAL
SYSTEM
CEREVISIAE.
and A. Wiemken
Ziirich,
5, CH-8092
Department Ziirich,
of General
Botany,
Switzerland
14,1976
Thermolysin, a commercial bacterial proteinase, greatly activated the arginine transport system of isolated yeast vacuoles. Pronase had the same effect at low concentrations, but rapidly inactivated the transport system at higher concentrations. Arginine specifically protected the transport system The protective effect of other amino acids form the inactivation by pronase. correlated well with their affinity for the transport system. It is concluded that both thermolysin and pronase attack a membrane protein which restrains the transport of arginine, whereas the protein which carries the specific binding site of this transport system can be destroyed only by pronase.
summary:
Vacuoles
isolated
active
transport
system
is mediated
of proteinases. Saccharide attack
system
Material
Preparation
for
which, (2),
of the vacuoles
spheroplasts
arginine
We considered residues
and
yeast
by a membrane
of proteases
surface
from
(1).
protein
vacuoles it
is
The question
suitable
for
protect
shown to be absent
contain
whether
can be examined
suspected,
have been
and purified
this
by studying
a highly transport the effect
such an experiment: the membrane from
from
the outer
the membrane
(3).
Methods:
of yeast
spheroplasts
and vacuoles
Spheroplasts were obtained from growing cultures of Saccharomyces cerevisiae (strain LBG H 1022, Institute for Microbiology, ETH, Ziirich). The spheroplasts were disrupted under isotonic conditions (0.6 M sorbitol containing 5 mM TrisPipes, pH 6.8 [TP-buffer])8by polybase-induced lysis as described (4) using 100 ug DEAE-dextran per 10 spheroplasts. The vacuoles were separated from the homogenate as described (4) but the method was scaled up by using a zonal rotor (type Beckman Ti-14). The homogenate was layered on a gradient 193 Copyrighr All rights
0 1976 by Academic Press, of reproduction in an>> form
Inc. reserved.
Vol. 73, No. 1,1976
BIOCHEMICAL
AND BIOPHYSICAL RESEARCH COMMUNICATIONS
consisting of two washing layers (0.5 M sorbitol with 0.1 M sucrose, 100 ml, and 0.45 M sorbitol with 0.15 M sucrose, 100 ml, respectively) and a reception layer (0.6 M sucrose, 100 ml) on top of which the vacuoles float after centrifugation. All solutions were buffered with TP-buffer. After 30 min centrifugation at 100'000 x g, the gradient was displaced by 30 % sucrose and the fractions containing the vacuoles were combined. They were mixed with 4 volumes of 0.6 M sorbitol and the vacuoles sedimentated by 30 min centrifugation at 2'000 x g. The purified vacuoles were resuspended in 0.6 M sorbitol with TP-buffer, at a final concentration of 5 x 107 vacuoles per ml. Protease
treatment
of the vacuoles
and assay
for
arginine
transport
1 ml portions of purified vacuoles were preincubated for 5 min at 25' C and then mixed with 50 ~1 of protease solution prepared with 0.6 M sorbitol containing TP-buffer and 10 mM CaC12. After specified intervals the vacuoles were separated from the proteases by centrifugation through a discontinuous isotonic density gradient (1). The vacuoles were taken up in 0.6 M sorbitol with TP-buffer, and the initial rate of the transport of 100 IJM L-E3H]arginine was determined as described (1). Chemicals
and protease
preparations
L-[3H]arginine was obtained from New England Nuclear, Boston, USA. Pronase was purchased from Koch-Light, Colnbrook Bucks, England, and Thermolysin (Protease type X) from Sigma, St.Louis, USA. One protealytic unit* was defined as the amount of protease which liberates 1 ~01 acid soluble tyrosine per min from 1 % casein under the conditions used for the pgotease treatment of the vacuoles (0.6 M sorbitol; TP-buffer; 0.5 M CaC12; 25 C). Results
and Discussion
Activation
of vacuolar
The effect
of incubation
preparation first
consisting
tested.
transport
and ranged
experiments. transport
It in the
Apparently As compared acids
were
sedimentated * Abbreviation:
with
The maximal
for
the untreated
has been
found
1 proteolytic
thermolysin,
-depending with
activity
a bacterial
proteolytic
thermolysin
protease
enzyme, activated
was attained
the vacuoles
control
after
was
their 10 min with
1U
in different
with
a low absolute
rate
of
upon
treatment
thermoysin.
controls.
of vacuoles
in the
2+
170 to 600 % of the
untreated
recovered
Ca
of vacuoles
from
by thermolysin
with
of a single
was higher
a fraction
transport
of vacuoles
The treatment
of arginine.
thermolysin
arginine
was lysed only
controls, sediment.
The amount
to be a reliable unit
about
= 1 U
194
with
70 % of the vacuolar
of vacuolar
measure
for
amino
the amount
amino
acids of intact
Vol. 73, No. 1, 1976
BIOCHEMICAL
AND BIOPHYSICAL
RESEARCH COMMUNICATIONS
control
z
5 Perlad
1: Thermolysin
I
0 0
Fig.
.
lOU/ml+O5mM EDTA
c1. z @J 10
of mcubatmn
activates
15
wth
thermolysln
the vacuolar
20 lm~ni
transport
system
5 x lo7 vacuoles per ml were incubated with 50 ul of thermolysin (1.0 or 0.2 U) preincubated either with 10 mM CaC12 or 10 mM Tris-EDTA. At the time indicated the vacuoles were separated from the incubation mixture by centrifugation through discontinuous density gradients, resuspended in 0.6 M sorbitol with 5 mM Tris-Pipes, pH 6.8, and assayed for the initial transport rate of 100 UM L-[3H]arginine.
vacuoles calculation Under
and therefore
served
of the transport
rate.
(l),
the assay
activity
conditions
This
indicates
against
The increase either
the
in transport
as a proteolytic
dissection
effect
Pronase,
a protease
a high
potency
3.3 mU pronase
per
apparent.
which
native
of the
2).
However,
(Fig.
proteolytic
arginine
followed
1).
action.
can be explained carrier
proteolytic
inactivation
195
of
sites
or as a
of the carrier.
transport
when higher
activity
system
the mobility
was next
activated
a concomitant transport
hidden
several
proteins,
5 x lo7 vacuoles (Fig.
transport
by thermolysin
containing
the
the proteolytic
is due to its
arginine
for
in the presence
arginine
restrains
on vacuolar
(15 - 67 mu), The decay
induced
protein
to degrade
inhibited
of preexisting
preparation
same way as thermolysin applied
activity
of pronase
on the
of thermolysin
liberation
of a membrane
The dual
were
effect
of reference
Correspondingly
casein.
had no effect
that
as a basis
0.5 mM EDTA completely
of thermolysin
0.5mM EDTA thermolysin
always
examined.
enzymes with A ratio
transport pronase of the first
of
in the concentrations system order
became kinetics
Vol. 73, No. 1, 1976
BIOCHEMICAL
AND BIOPHYSICAL
RESEARCH COMMUNICATIONS
/.E Etj;15 0F
P “s 1 P
50 30 20 0
5 Period
Fig.
2: Effect of various transport Fig.
As
1, but
10
pronase
thermolysin
15
of incubation
by 3.3,
.
Fig.
3: Protection inactivation
taken
the
first
0.7 min -1 for A possible fact
7 min if
as the value
that
resuspension
arginine
15, 27, 67 mU of pronase.
Arg .
10
of incubation
with pronase
Iminl
of the arginine transport system from proteolytic by its substrates, arginine and lysine
As Fig. 2, but with before the addition
over
on vacuolar
67mU/ml+2.5m.M
5 Period
Iminl
concentrations
replaced
0
20
with pronase
for
addition of 10 ~1 0.2 M L-arginine of pronase.
the maximally zero
time.
activatedtransport
The decay
15 mU and 67 mU pronase,
explanation some vacuoles and transport
for were
the
slowed
destroyed assays,
or L-lysine
rate
constants
were
0.14
1 min
(260 %> was min -1 and
respectively. decay
after
the
by the pronase
30 % less
196
vacuoles
first
7 min lies
treatment: were
in the
After
sedimentated
than
BIOCHEMICAL
Vol. 73, No. 1,1976
in the
controls
arginine
pool
system
of the
Substrate
for
remaining
vacuoles,
acids
of more than
the destroyed
protect
RESEARCH COMMUNICATIONS
vacuoles
as demonstrated
the vacuolar
7 min.
may protect
The internal the
transport
below.
arginine
transport
system
activated
the
from
inactivation
transport
system
is not
identical
Tab.
incubations
from
In the presence
This
pronase
liberated
amino
proteolytic
all
AND BIOPHYSICAL
of 2.5 mM L-arginine, (Fig.
3) but
no longer
due to an inhibition in the
absence
pronase
displayed
of pronase
or presence
L: Effect of different amino the proteolytic inactivation
still
as its
the
subsequent
activity
against
arginine inactivation. casein
was
of 2.5 mM arginine.
acids on the transport of L-arginine of the arginine transport system
and on
The transport rate of vacuoles for 100 PM L-[3H]arginine was determined in the presence of the amino acids listed. Vacuoles of the same batch were used for studying the effect of the amino acids on the kinetic of proteolytic 7 inactivation of the arginine transport system. 5 x 10 vacuoles in 1 ml were incubated for 2, 5, 10 and 20 min with 50 ~1 pronase (67 mU) in the presence of 0.5 mM CaC12and the amino acids listed. The vacuoles were then separated from the incubation mixture by centrifugation through discontinuous density gradients, resuspended, and their initial rate of arginine transport determined. From plots as shown in Fig. 3 for arginine and lysine, the rate constants of the proteolytic inactivation of the arginine transport system were estimated. Amino
acid
Cont.
mM
Transport rate of 100 uM L-[3H]arginine
Rate constant of the proteolytic inactivation of the arginine carrier
pmoles per nmol amino acid per min
%
min
-1
%
7.7
100
0.56
100
L-leucine
2
6.7
87
0.56
100
Glysine
2
3.4
44
0.26
46
L-histidine
2
2.2
29
0.19
34
D-atginine
2
1.0
13
0.075
13
L-arginine
0.5
1.3
17
0.12
21
L-arginine
2
0.6
8
0.00
0
197
Vol. 73, No. 1,1976
BIOCHEMICAL
The presence
of 2.5 mM L-lysine,
the vacuolar
arginine
only
by ca.
In the experiment amino
acids
measuring
for their
respective
amino arginine
ability
attribute
transport
site
arginine
for
However,
this
unoccupied
spheroplasts
to bind
the present vacuolar vacuole
for
of the system
of a number
were
established
The ability
of
by
of the
of the arginine
of vacuoles.
proteolytic
For
each of the
inactivation
of the
to the respective
affinity
for
transport
attack
have
acid
the same cause;
to the
specific
the protein system
by pronase
arginine
site
carrying
is destroyed
occurs
transport
of intact
Possibly
membrane
only
if
we of the
the specific by pronase.
the
site
is
(3)
of spheroplasts
spheroplasts
(1)
of pronase the
(up to 1200 mU per
saccharide
protect
was found
residues
the transport
covering system
to be 5 x lo7 the
outer
of the
by pronase.
this A are
susceptibility
connection distributed of which is
exposed
was found
effects
that
concentrations
attack in
both
molecule.
communication,
(G),
same batch
closely
that
of the
system
plasma
membrane,
of decay
inactivation
of the amino
on the
Concanavalin the
the
and conclude
10 min).
from
system transport.
to inhibit
of the
to high
interesting
surface,
with
suggest
transport
of the
affinity
system.
system
for
a poor
affinities
transport
corresponded
binding
even
with
the rate
proteolytic
ability
system
has no effect
spheroplasts
is
the
by a substrate
resistant
It
was tested
effect
The arginine
reduced
arginine
to inhibit
to the binding
arginine
surface
acids
strongly
this
acid
1, the relative
to inhibit
transport
findings
Pronase
arginine
transport
the arginine These
the vacuolar
tested,
amino
RESEARCH COMMUNICATIONS
3). in Tab.
system acids
system
presented
amino
transport
a basic
transport
70 % (Fig.
AND BIOPHYSICAL
free
to several
to be covered
to consider
how saccharide
on the vacuolar to pronase of them. potent with 198
membrane
and thermolysin
However proteases saccharide
the
residues
able
(3).
outer
we examined
inner
surface
located
within
residues.
Its
of the the
in
Vol. 73, No. 1, 1976
BIOCHEMICAL
AND BIOPHYSICAL
RESEARCH COMMUNICATIONS
Acknowledgements: We like to express our sincere thanks to B. Coombe, Ph. Matile and S. Turler for their help in preparing the manuscript. This was supported by the Swiss National Science Foundation.
work
References: 1. Boller, Th., Diirr, M., and Wiemken, A. (1975) Eur. J. Biochem. lft, 81-91. R. (1972) J. Biol. Chem. 247, 2. Kahlenberg, A., Dolansky, D., and Rohrlick, 4572-4576. 3. Boller, Th., Diirr, M., and Wiemken, A. (1976) Arch. Microbial. 109, 115-118. 4. Diirr, M., Boller, Th., and Wiemken, A. (1975) Arch. Microbial. 105, 319-327. 101, 45-57. 5. Wiemken, A., and Diirr, M. (1974) Arch. Microbial. 6. Lenney, J.F., Matile, Ph., Wiemken, A., Schellenberg, M., and Meyer, J. (1974) Biochem. Biophys. Res. Cormnun. 60, 13781383.
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