454
VERNON H. CHELDELIN, CHIH H. WANG, AND TSOO E. KING
The conclusion is drawn from the consideration that the fructoses-phosphate derived from the labeled gluconate should bear the labeling patterns shown in Scheme 3 (14, 146) (see also Fig. 3):
1 C
, A
4 C-+6
5 A
1
1
6 C
r l C0 2
+
2 C
1
1
3 C
4 A
I 1
5 C
1 1
ß c
C 2 2 2 2
C 3 3 3 3
->C 2 2 3 3
C4444+C44
C5555
C55
C6666
C66
4 F-6-P + 2 triose-P
Further catabolism of these fructose-6-P molecules may be predicted
as follows:
Let us consider the fate of gluconate-C-2: In Table IV, data are
given for the total yields of C
14 0 2 from individual carbon atoms of
glucose and gluconate. For gluconate-2-C
14 , the fraction decarboxylated
is 88%. This represents the maximum amount of substrate gluconate that
could have traversed the cycle (and the probable actual amount that
did so).
According to Beevers' scheme, the re-formed fructose-P (from gluconate) will have the original C-2 from gluconate in carbons A and C
of the fructose; 67% of this will be in carbon A, 33% in carbon C.
If we now assume that the reformed fructose-6-P behaves like adTABLE IV
PERCENTAGE RECOVERIES OF INDIVIDUAL CARBON ATOMS IN
Bacillus subtilis OXIDATIONS
Substrate
Glucose-1
Glucose-2
Glucose-3
Glucose-3,4
Glucose-4
Glucose-6
Gluconate-1
Gluconate-2
Gluconate-3
Gluconate-3,4
Gluconate-4
Gluconate-6
C0 2
60
60
67
77
87
41
88
54
54
63
72
44
Cells
22
25
19
15
11
23
1
22
31
19
7
36
Medium
13
16
16
12
8
41
11
18
17
15
13
18
Total
95
101
102
104
106 (calc.)
105
100
94
102
97
92 (calc.)
98