Histidine

[jmyhre]

Hi,

As usual lately I'm not sure I understand the question but here goes nothing...

"Consider the essential amino acid histidine. List at least 4 possible fates or roles that histidine plays in metabolism. Consider both general fates of amino acids and specific fates of histidine"

Ok, I have found a few fates of histidine as it is metabolized such as:
1. Histidine is converted to urocanate in the liver or skin. In skin urocanic acid is produced to absorb UV rays.
2. In liver urocanate is further processed into ammonia, glutamate and a 1-C fragment that it used in the folate coenzyme system.
3. Decarboxylation into histamine which is found predominately in mast cells and plays important roles in immune function and as a paracrine agent acting on the stomach.
4.??

However, I keep re-reading the question and it seems to be asking the role of histidine in fuel metabolism??? So far I haven't found any roles specific to histidine. Just things that are standard like transamination into acetyl Co-A. I know this is long winded but any help would be greatly appreciated.

Thanks,
J