Amino Acids That Are Converted To Pyruvate

There are six amino acids(including the side of tryptophan) that are converted to pyruvate. alanine is converted into pyruvate in a -ketoglutarate depending transamination reaction is converted into pyruvate in a ketoglutarate dependent transamination reaction catalyzed by alanine aminotransferase pyruvate can be either oxidatively decarboxylated to acetyl CoA or converted to oxaloacetate (OAA) these two products can have differentfates depending on the cellular requirements. Acetyl CoA can be enter anaplerotic role. the fate of glutamate has been discussed.

the major route of glucine catabolism is the glycine cleavage (or glycine decarboxylase)/glycine synthase multienzyme complex, present in the mitochondria. the four enzymatic steps PLP, ionic acid ,THF, FAD and NAD+. the net outcone of the reaction of.

the enzyme are: (1) glycine decarboxylase (PLP)

                          (2) lipoamide containing amino methyl transferase

                          (3) methylene THF-synthesizing enzyne and,

                          (4) dihydrolipoyl dehydrogenase

the primarly catabolism os serine through a ,B elimination of water catalyzed by serine dehydratase. it also result in deamination of the amino acid by non enzymatic tautomarisation of amino acrylate intermadiate, followed by hydrolysis to pyruvate as the other product.

glycine can also be converted to serine by serine hydroxy transferase the enzyme catalyses the condensation of  1Cunit derived methylene -THF to glycine to form serine the 1C unit is provided by glycine cleavage system. in this conversion, two glycine yield serine, NH₄⁺ ,co₂ and NADH.

the serine hydroxy methyl transferase catalyzed reaction bidirectional and both serine and glycine are interconvertile incidentally it is the major contributor of 1C unit to THF.

the catabolism of l-cysteine occurs by multiple routes. the major pathways in animals is the direct oxidation (cysteine sulphinate)pathways. in the pathways cysteine is converted to pyruvate in three steps. it begins with the oxidation of cysteine sulphinate to (3-sulphinoalanine) by cysteine dioxygenase.in the next step it is transaminated to B-sulphinyl pyruvate and is finally de-sulphurated to pyruvate. cysteine. sulphinate is also a biosynthetic precursor which can be diverted to from taurine that in turn conjugates with cholic acid to from taurocholic acid (bile acid).

.