Group transfer enzymes

Enzyme Coenzyme or cofactor Delivered atom or group Alcohol-dehydrogenase Catechol-O-methyltransferase Homocysteine-methyl-transferase e.g. Formyl-transferase Amino acid-transaminases Kinases NADP S-adenosyl methionine Cobalamin R-tetrahydrofolate pyridoxal phosphate Mg-ATP Hydride ion (H-atom + electron) Methyl group methyl, methylene, formyl group amino group phosphate group

ATP and phosphoryl transfer reactions Possible structures of the Mg–ATP complex

ATP and phosphoryl transfer reactions ATP 4– + H 2 O = H + + HPO 4 2– + ADP 3–  r G 0 = 30,5 kJ/mol (i) Storage of energy for later use (creatin →creatin-phosphate) (ii) change in the conformation of a protein to control enzyme activity or transport process or in order to perform work (iii) In order to cover the energy need of the various metabolic processes, etc.

ATP and phosphoryl transfer reactions Na +,K + pump Phosphorylation of protein side chains Glycolysis glucose + Mg-ATP → glucose-6-phosphate + Mg-ADP R-XH + Mg-ATP → R-X-PO Mg-ADP R-COO - + Mg-ATP → R-C(O)-O-PO Mg-ADP

ATP and phosphoryl transfer reactions An example for the formation of ATP 1,3-bisphosphoglycerate3-phosphoglycerate

ATP and phosphoryl transfer reactions A possible mechanism of the protein kinases

ATP and phosphoryl transfer reactions A reaction catalysed by glutamine synthase

ATP and phosporyl transfer reactions Mechanism of glutamine syntethase NH 3

Structure of methylcobalamin (X = CH 3 ) Methylcobalamin and B 12 coenzyme

(corrin)Co III -CH 3  (corrin)Co III + CH 3 – (corrin)Co III -CH 3  (corrin)Co II + CH 3 ● (corrin)Co III -CH 3  (corrin)Co I + CH 3 + Methylcobalamin and B 12 coenzyme

The reaction catalysed by homocystein-methyl-transferase Methylcobalamin and B 12 coenzyme

General mechanism of the B 12 coenzyme dependent isomerases and several representants General mechanism Enzyme Glutamate-isomerase Methylmalonyl-coenzyme A Diol-dehydratase Ethanolamine-ammonia-lyase R1HHHHR1HHHH R 2 CH(NH 2 )(COOH) H OH NH 2 R 3 H COO - H R 4 H CH 3 H X COO - C(O)-S-CoA OH Methylcobalamin and B 12 coenzyme

B 12 coenzyme (corrin)Co II + R-CH 2 + B 12 coenzyme (corrin)Co II + R-CH 2 + Methylcobalamin and B 12 coenzyme General mechanism of the B 12 coenzyme-dependent isomerase:

The (first step) product of the reactions catalysed by the B 12 coenzyme- dependent dehydratases gives an aldehyde by spontanaous water liberation. Methylcobalamin and B 12 coenzyme