Manganese adenosine triphosphate

The simplest use of manganese is as part of a metal cofactor such as manganese(II) adenosine triphosphate, [Mn(II)ATP2-]. The metal complex is usually found as the bidentate [Mn(II)0,7-ATP2 ] (3, 4) as illustrated in Figure 1. Enzyme specificity for Mg(II), Mn(II), or Ca(II) ATP complexes is dependent on a variety of factors however, once selected, each metal apparently functions in an analogous manner. The metal ion serves two main purposes. First, based on the coordination geometry... 

Sigel, H. and Naumartn, C. F., Ternary complexes in solution. XXIV. Metal ion bridging of stacked purine-indole adducts. The mixed-ligand complexes of adenosine 5 -triphosphate, tryptophan, and manganese(II), copper(II), or zinc(II), /. Am. Chem. Soc., 98(3], 730, 1976. 

Guanosine 5 -triphosphate, cytidine 5 -triphosphate, and uridine 5 -pyro-phosphate cannot replace adenosine 5 -triphosphate. Magnesium ion is required for this reaction it may be replaced by manganese, zinc, and cobalt divalent ions. The reaction rate is increased when the temperature is raised from 30 to 55°, but, at 65°, the reaction proceeds only during the first 10 minutes, and, at 75°, no reaction occurs. The optimal pH is 6.5-7.5. Compounds that interact with the sulfhydryl group inhibit the reaction p-chloromercuribenzoate shows 100% inhibition at 0.5 mM. 

On a dry weight basis, Saccharomyces contains 3% to 5% phosphate, 2.5% potassium, 0.3% to 0.4% magnesium, 0.5% sulfur, and trace amounts of calcium, chlorine, copper, iron, zinc, and manganese (Monk, 1994 Walker, 1998). Yeast must be supplied with a source of phosphate, which is incorporated into nucleic acids, phospholipids, adenosine-5 -triphosphate (ATP), and other compounds. Potassium is necessary for uptake of phosphate, and a deficiency may be linked to sluggish alcoholic fermentations (Kudo et ak, 1988). Other minerals needed by Saccharomyces during fermentation have a variety of functions but are used primarily as enzyme activators. 

---