Glucose-6-P dehydrogenase

ATP NADH Disappearance Hexokinase and Glucose-6-P Dehydrogenase Adenylate Kinase, Creatine Kinase ... 

Fructose 6-P NADH Formation Glucosephosphate Isomerase, Glucose-6-P Dehydrogenase Fructokinase ... 

Ovalbumin Conalbumin Ovomucoid Lysozyme Vitellogenin apo-VLDL Glucose-6-P-dehydrogenase Oviduct Oviduct (liver) Oviduct Oviduct Liver Liver Uterus Thyroid Hormones Carbamyl phosphate synthase Growth hormone Prolactin ( ) a-Glycerophosphate dehydrogenase Malic enzyme Liver Pituitary Pituitary Liver (mitochondria) Liver... 

Fig. 22. Schematic presentation of the enzymatic synthesis of UDP-GalNH2 (33) including cofactor regeneration systems. A nucleoside monophosphate kinase (EC 2.7.7.4), B sucrose synthase (EC 2.4.1.13), C gal-l-P uridyltransferase (EC 2.7.7.12), D phosphoglucomutase (EC 2.7.5.1), E glucose-6-P dehydrogenase (EC 1.1.1.49), F lactate dehydrogenase (EC 1.1.1.27), G pyruvate kinase (EC 2.7.1.40) [319]...

See p. 115 in Biochemistry (2nd ed.) for a discussion of glucose-6-P dehydrogenase deficiency. 

Glucose 6-P-dehydrogenase deficiency results in a decrease in NADPH and GSH synthesis, making the cell more sensitive to oxidative agents, such as primaquine. This causes hemolysis. 

The CK assay has a lag phase of several minutes for specimens with a normal CK activity even in the presence of a large excess of the activities ol hexokinase (EC 2.7.1.1) and glucose-6-P-dehydrogenase (G-6-PDH, EC 1.1.1.49). A long lag phase for the CK assay is predictable based on the above discussion for a two-step assay. Specimens with increased CK activities generally have shorter lag phases. 

Inhibits adenylate cyclase, Na,K-ATPase, catalase, catechol o-methyltransferase, fetredoxin-NADP reductase, glucose-6-P dehydrogenase, lipase, fatty acid oxygenase, peroxidase, cAMP phosphodiesterase, tyrosinase, urea levels. 

Ribose-5-P only Only the nonoxidative reactions. High NADPH Inhibits glucose- 6-P dehydrogenase, so transketolase and transaldolase will be used to convert fructose-6-P and glyceraldehyde-3-P to rlbose-5-P. 

Fig, 17.6 Hexose monophosphate pathway. 1, glucose-6-P-dehydrogenase 2, 6-P-gluconolactonase 3,6-P-gluconate dehydrogenase 4, phosphoribose isomerase 5, phosphoketopentose epimerase 6, transketolase 7, transaldolase TPP, thiamine pyrophosphate. 

Fig. 1. Procedure for the electrophoretic separation and detection of the three CPK isoenzymes MM-CPK, MB-CPK, and BB-CPK. Staining for enzymic activities is achieved by means of a sandwich technique. Unsoluble formazan is deposited at the locations of CPK activity. NBT, Nitro-blue-tetrazolium PMS, phenazine methosulfate HEX, hexokinase and G-6-PDH, glucose-6-P-dehydrogenase.

That either the oxidative or the nonoxidative branch alone is able to provide sufficient pentose phosphates to support growth has been demonstrated by studies of various microorganisms. Thus, Candida (Torxda) ulilis apparently uses the oxidative pathway only, even though it contains transaldolase and transketolase (16, 17). In contrast, Alcaligenes faecalis and Pseudomonas saccharophilia lack the oxidative branch (18,19). In some cases still different pathways of pentose phosphate synthesis may occur in bacteria. Human erythrocytes deficient in glucose-6-P dehydrogenase can synthesize pentose phosphates adequately via the nonoxidative branch (80). 

Drugs may induce enzymes that result in their own destruction. For example, phenobarhital has been found to induce an increase in glucose-6-P dehydrogenase which would serve to increase NADPH [Platt and Cockrill, 115]. In insects treated with DDT, the NADPH concentration was also found to be increased a shift in glucose metabolism occurred, 77% being used in the pentose-P pathway as compared to 21% in the controls [Terriere, 116]. Barbiturates and chloro-butanol doubled the activity in the liver cytosol of UDPG-dehydrogenase... 

Barbiturate, AIA, drugs, chloretone, benzpyrene Glucose-6-P-pentose-P Glucose-6-P dehydrogenase (nonmicrosomal), UDP-transglucuronidase (microsomal). Limiting enzymes for ascorbate synthesis ... 

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