(thing) by CrazyIvan Sun Apr 09 2000 at 4:04:53
Basic Amino acid. Positively charged at neutral pH. Side chain is a pentagon-shaped imidazole ring, with a partial positive charge.

Formula: C6H9N3O2
Molecular Weight: 155.15
Three-letter code: His
One-letter code: H
del.icio.us Facebook Digg StumbleUpon Reddit (I like it!)
(thing) by EPICAC Sat Oct 27 2001 at 5:57:39
Histidine has the following structure: 

    COOH
    |
H2N-C-H
    |
    CH2
    |
    C--NH
   ||    \
   ||    CH       
   ||   //
    C---Na
    |
    H
The nitrogen labled 'a' can be protonated, and has a pKa of 6.04.

Histidine is a very catalytically active molecule. It plays critical roles in enzymes such as RNase and in Serine Proteases.

del.icio.us Facebook Digg StumbleUpon Reddit (I like it!)
Y'know, if you log in, you can write something here, or contact authors directly on the site. Create a New User if you don't already have an account.