CHAPTER
9
Saccharides: Alternate Routes of Metabolism*!
VERNON H. CHELDELIN, CHIH H. WANG, and Tsoo E. KING
Department
of Chemistry and Science Research
Institute,
Oregon State University, Corvallis, Oregon
I. The Pentose Cycle
428
A. Historical Introduction
428
B. Outline of the Pentose Cycle
429
C. Enzymes of the Pentose Cycle
433
II. The Glucuronate Pathway
440
III. Heterofermentative Lactic Acid Degradation of Glucose ....
440
IV. The Entner-Doudoroff Scheme
442
V. Comparative Studies
443
A. Examination of Methodology
443
B. Possible Role of the Pentose Cycle in Metabolism
....
465
VI. Direct Oxidations of Glucose and PolyoLs
466
A. Direct Oxidation of Glucose
466
B. Multiple Catabolic Pathways of Glucose in Acetobacter suhoxydans
471
C. Further Oxidation of Gluconic Acid
474
D. Polyol Dehydrogenases
475
References
492
* Supported by grants from the National Institutes of Health, the Atomic
Energy Commission, the National Science Foundation, the American Heart Association, the American Cancer Society, the Life Insurance Medical Research Fund, and
the Nutrition Foundation. Published with the approval of the Monographs Publications Committee, Oregon State University, Paper No. 401, School of Science, Department of Chemistry. Acknowledgment is made to Dr. C. P. Lee for helpful advice.
f The following abbreviations are used throughout this paper: ATP, adenosine
triphosphate; DPN, diphosphopyridine nucleotide; E-4-P, erythrose-4-phosphate;
F-6-P, fructose-6-phosphate; FMN, FAD, flavin mono- or dinucleotide; G-6-P,
glucose-6-phosphate; GLA-P, glyceraldehyde-3-phosphate; HMP pathway, hexose
monophosphate pathway (phosphogluconate cleavage; this usually does not imply
the complete pentose cycle); KDPG, 2-keto-3-deoxy-6-phosphogluconate; 6-PGA,
6-phosphogluconate; PKPE, phosphoketopentose epimerase; PPI, pentose phosphate
isomerase; R-5-P, ribose-5-phosphate; RNA, ribonucleic acid; RTU, relative time
unit (time required for disappearance of an added test substrate from the medium);
Ru-5-P, ribulose-5-phosphate; SH-7-P, sedoheptulose-7-phosphate; TPN, triphosphopyridine nucleotide; Xu-5-P, xylulose-5-phosphate.
427
9
Saccharides: Alternate Routes of Metabolism*!
VERNON H. CHELDELIN, CHIH H. WANG, and Tsoo E. KING
Department
of Chemistry and Science Research
Institute,
Oregon State University, Corvallis, Oregon
I. The Pentose Cycle
428
A. Historical Introduction
428
B. Outline of the Pentose Cycle
429
C. Enzymes of the Pentose Cycle
433
II. The Glucuronate Pathway
440
III. Heterofermentative Lactic Acid Degradation of Glucose ....
440
IV. The Entner-Doudoroff Scheme
442
V. Comparative Studies
443
A. Examination of Methodology
443
B. Possible Role of the Pentose Cycle in Metabolism
....
465
VI. Direct Oxidations of Glucose and PolyoLs
466
A. Direct Oxidation of Glucose
466
B. Multiple Catabolic Pathways of Glucose in Acetobacter suhoxydans
471
C. Further Oxidation of Gluconic Acid
474
D. Polyol Dehydrogenases
475
References
492
* Supported by grants from the National Institutes of Health, the Atomic
Energy Commission, the National Science Foundation, the American Heart Association, the American Cancer Society, the Life Insurance Medical Research Fund, and
the Nutrition Foundation. Published with the approval of the Monographs Publications Committee, Oregon State University, Paper No. 401, School of Science, Department of Chemistry. Acknowledgment is made to Dr. C. P. Lee for helpful advice.
f The following abbreviations are used throughout this paper: ATP, adenosine
triphosphate; DPN, diphosphopyridine nucleotide; E-4-P, erythrose-4-phosphate;
F-6-P, fructose-6-phosphate; FMN, FAD, flavin mono- or dinucleotide; G-6-P,
glucose-6-phosphate; GLA-P, glyceraldehyde-3-phosphate; HMP pathway, hexose
monophosphate pathway (phosphogluconate cleavage; this usually does not imply
the complete pentose cycle); KDPG, 2-keto-3-deoxy-6-phosphogluconate; 6-PGA,
6-phosphogluconate; PKPE, phosphoketopentose epimerase; PPI, pentose phosphate
isomerase; R-5-P, ribose-5-phosphate; RNA, ribonucleic acid; RTU, relative time
unit (time required for disappearance of an added test substrate from the medium);
Ru-5-P, ribulose-5-phosphate; SH-7-P, sedoheptulose-7-phosphate; TPN, triphosphopyridine nucleotide; Xu-5-P, xylulose-5-phosphate.
427