This intermediate is then open to further reaction with porphobilinogen ( 1 and 2 repeated three more times ).
12.
It catalyzes the head to tail condensation of four porphobilinogen molecules into the linear hydroxymethylbilane while releasing four ammonia molecules.
13.
The structure of 40-42 kDa porphobilinogen deaminase, which is highly conserved amongst organisms, consists of three domains.
14.
Two molecules of dALA are then combined by porphobilinogen synthase to give porphobilinogen ( PBG ), which contains a pyrrole ring.
15.
Two molecules of dALA are then combined by porphobilinogen synthase to give porphobilinogen ( PBG ), which contains a pyrrole ring.
16.
Subsequent treatment with anti-psychotics increases the accumulation of porphobilinogen, thus aggravating the disease enough that it may prove fatal.
17.
The first step is believed to involve an E1 elimination of ammonia from porphobilinogen, generating a carbocation intermediate ( 1 ).
18.
However, without porphobilinogen deaminase, a necessary cytoplasmic enzyme, heme synthesis cannot finish, and the metabolite porphobilinogen accumulates in the cytoplasm.
19.
However, without porphobilinogen deaminase, a necessary cytoplasmic enzyme, heme synthesis cannot finish, and the metabolite porphobilinogen accumulates in the cytoplasm.
20.
Hydroxymethyl bilane is a major anabolic product, from the biosynthetic reaction of porphobilinogen ( PBG ) and uroporphyrinogen I synthase ( known as porphobilinogen deaminase ).
