8. POLYSACCHARIDASES
381
has antigenic properties, when injected into rabbits, has been demonstrated by McGeachin and Reynolds (194). These authors were able
to inhibit a sample of hog pancreatic amylase to the extent of 95% by
Source of
a-amylase
Pig pancreas (71)
Human pancreas {74)
Human saliva (66)
Barley malt (129, 130)
B. suhtilis (189)
A. oryzae (170)
TABLE XII
STABILITY OF «-AMYLASES
pH Optimum
of stability
7.0-8.5
4.8-11
4.8-11
4.9-9.1
4.8-12«*
5.5-8.5
Stability
0 in
the presence
of EDTA
b (193)
0, 30
c
100
82.5, 92
c
100
Stabilization
by
Ca
2+e
Ca
2+
/
Ca
2+
Ca
2+
α Approximate percentage of activity recovery after 1 hour at pH 7.2, 25°, in the
presence of 0.005 M EDTA.
6 Sodium ethylenediamine tetraacetate.
c The two figures represent two amylase preparations obtained by different methods.
d In the presence of Ca
2+ .
e Also by Mn
2+ , Ba
2+ , Mg
2+ and Ni
2+ .
f Requires Ca
2+ for activity.
precipitation with the specific rabbit antiserum. They further observed
that their antiamylase was able to inhibit to a considerable extent hog
amylases from various other tissues or fluids, with the exception, howTABLE XIII
CHEMICAL COMPOSITION OF «-AMYLASES
Source of
«-amylase
Pig pancreas
Human pancreas
Human saliva
Barley malt
B. suhtilis
A. oryzae
%N
15.8
15.8
15.8
13.4
15.8
12.9
%P
0.05
0.01
0.01
0.01
0.01
Metal
(193)
a
Ca
2+
Ca
2+
Ca
2+
Ca
2+
Ca
2+
Ca
2+
Groups essential for activity
—SH
+ (142)
—NH 2
(primary)
+ (82)
+ (142)
—OH
(tyrosyl)
+ (143)
a At least 1 gm. atom firmly bound calcium per mole protein.
ever, of hog liver amylase (see Table XIV), and they concluded that
hog amylases are more species specific than organ specific and that the
liver enzyme appears to be different from the amylases of the other
381
has antigenic properties, when injected into rabbits, has been demonstrated by McGeachin and Reynolds (194). These authors were able
to inhibit a sample of hog pancreatic amylase to the extent of 95% by
Source of
a-amylase
Pig pancreas (71)
Human pancreas {74)
Human saliva (66)
Barley malt (129, 130)
B. suhtilis (189)
A. oryzae (170)
TABLE XII
STABILITY OF «-AMYLASES
pH Optimum
of stability
7.0-8.5
4.8-11
4.8-11
4.9-9.1
4.8-12«*
5.5-8.5
Stability
0 in
the presence
of EDTA
b (193)
0, 30
c
100
82.5, 92
c
100
Stabilization
by
Ca
2+e
Ca
2+
/
Ca
2+
Ca
2+
α Approximate percentage of activity recovery after 1 hour at pH 7.2, 25°, in the
presence of 0.005 M EDTA.
6 Sodium ethylenediamine tetraacetate.
c The two figures represent two amylase preparations obtained by different methods.
d In the presence of Ca
2+ .
e Also by Mn
2+ , Ba
2+ , Mg
2+ and Ni
2+ .
f Requires Ca
2+ for activity.
precipitation with the specific rabbit antiserum. They further observed
that their antiamylase was able to inhibit to a considerable extent hog
amylases from various other tissues or fluids, with the exception, howTABLE XIII
CHEMICAL COMPOSITION OF «-AMYLASES
Source of
«-amylase
Pig pancreas
Human pancreas
Human saliva
Barley malt
B. suhtilis
A. oryzae
%N
15.8
15.8
15.8
13.4
15.8
12.9
%P
0.05
0.01
0.01
0.01
0.01
Metal
(193)
a
Ca
2+
Ca
2+
Ca
2+
Ca
2+
Ca
2+
Ca
2+
Groups essential for activity
—SH
+ (142)
—NH 2
(primary)
+ (82)
+ (142)
—OH
(tyrosyl)
+ (143)
a At least 1 gm. atom firmly bound calcium per mole protein.
ever, of hog liver amylase (see Table XIV), and they concluded that
hog amylases are more species specific than organ specific and that the
liver enzyme appears to be different from the amylases of the other