Acetol phosphate

Under mild conditions, chloro- and bromo-acetol phosphates (70), reactive analogues of dihydroxyacetone phosphate, inactivate yeast fructose... 

The enzyme also catalyzes the exchange of a proton from the solvent into the C-3 position of DHAP and of acetol phosphate (24, 25). 

As seen from the data in Table II, the enzyme enhances the eflFect of bound Mn on the C-3 protons of acetol phosphate, indicating the formation of an enzyme-Mn-substrate bridge complex. However, the enzyme-bound Mn has a smaller effect on the C-1 protons, indicating that the presence of the enzyme alters the structure of the Mn coordination complexes. Thus, in the absence of enzyme, from distance calculations and from stability constants, inorganic Mn forms a monodentate phosphate complex with acetol phosphate. 

Figure 5. Structures and mechanisms in aide-lase-Mn-substrate bridge complexes A. acetol phosphate, B. dihydroxyacetone phosphate Mechanism C is proposed for animal aldolases by analogy with A and B (from Ref, 22)...

The enzymes that catalyze these transformations have been partially purified from extracts of Neurospora. Imidazole glycerol phosphate is dehydrated by an enzyme named IGP dehydrase to form imidazole acetol phosphate. The dehydrase requires Mn++ and a sulfhydryl com-... 

The conversion of imidazole acetol phosphate to histidinol phosphate is catalyzed by a transaminase. This pyridoxal phosphate enzyme reacts... 

Relative Rates of Reaction ivith Imidazole Acetol Phosphate Tkansaminasb ... 

Compound Imidazole acetol phosphate a-Ketoglutarate of-Keto-5- a-Ketoadipate guanidovalerate ... 

The herbicide Amitrole (455) has several documented effects on metabolism. In E. coli, histidine and adenine together reverse the inhibition of growth by Amitrole, whereas adenine alone, but not histidine alone, partially relieves the inhibition. In the yeast T. cremoris, histidine alone, but not adenine alone, completely reverses the inhibition.A metabolite, identified as a conjugate of alanine and Amitrole, has been shown to accumulate in the medium of E. coli cultured in the presence of Amitrole it apparently competes with histidine for incorporation into protein.Unlike Amitrole, this metabolite does not inhibit the conversion of imidazole glycerol phosphate (IGP) to imidazole acetol phosphate by IGP dehydratase in Salmonella the reaction is part of the biosynthesis of histidine. 

Histidinol phoqihate a-ketoglutaric acid imidasol-acetol phosphate - - glutamic acid SOS... 

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