BIOC 302 Lecture Notes - Lecture 4: Phosphoribosyl Pyrophosphate, Nucleotidase, Xanthine
Document Summary
Talked about in last lecture this diagram doesn"t have the feedforward mechanism. All purine degradation leads to uric acid (but it might not stop there) Nucleotidase removes phosphate: 5" nucleotidase = removes the 5" phosphate. Nucleosidase phosphorylase uses phosphate to break the - N-glycosidic bond (not shown in this pathway but could be from guanosine to guanine + ribose-1-phosphate: products would be: nitrogenous base, and a ribose 1" phosphate. Nucleosidases uses h2o to degrade the -n-glycosidic bond. Deaminases take off the amino group, and leaves us with the keto/eno form of xanthine. Uric acid crystals will form in the extremities with a surrounding area of inflammation. Can be caused by a defect in an enzyme of purine metabolism or by reduced secretion of uric acid into the urinary tract. How to treat: shut down degradation of purine. Allopurinol irreversibly binds to xanthine oxidase (suicide inhibitor)
