Purple Acid Phosphatase
Figure
1.
Purple
acid phosphatases (PAP) (E.C. 3.1.3.2.) are metalloenzymes that hydrolyse phosphate esters and anhydrides under acidic
condition.It has many different
functions such as bacteria eliminating elements, bone metabolism in humans, and
phosphate uptake in plants. This acid can be helpful in cancer treatment with
anti-osteoporotic. Figure one shows PAP in a mammal. It has some secondary and tertiary
A
great 3D picture can be seen by clicking the link below.
Active sites: Fe(III) and Zn(II) are part
of the center of the active site. This is shown from figure 2 by site M1 and M2. M1 represents the tight binding site and M2 the lower affinity site.
Figure
2.
Chemical formula: ligand components C8 H15 N O6, Fe, and Zn
(for a kidney purple acid phosphatase)
Molecular weight: the
molecular weight of its polypeptides is 50.0 kD and multimer experimental is
130.0 kD (pubs.acs.org)
Reaction catalyzed: phosphate monoester + H2O <=> phosphate + an alcohol
Rate information: As stated in the Journal of the Chemical Society, "The
rate-determining step in the binding of phosphate to the pink active form (FeIIFeIII) of purple acid phosphatase monitored at 620 nm is
independent of phosphate, indicating rapid binding to FeII as a first stage, followed by
rate-determining bridging to the chromophoric iron(III) centre (pKa
4.02)"
4.02)"
Source:
http://www.rcsb.org/pdb/explore/explore.do?structureId=1KBP
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2267794/
http://pubs.rsc.org/en/Content/ArticleLanding/1992/DT/dt9920002135
http://www.siumed.edu/~eniederhoffer/chime_rasmol/iron_proteins/p_acid_phos_rc.htm
