PMID- 9566736
OWN - NLM
STAT- MEDLINE
DCOM- 19980508
LR  - 20190826
IS  - 0009-2797 (Print)
IS  - 0009-2797 (Linking)
VI  - 109
IP  - 1-3
DP  - 1998 Feb 20
TI  - Cooperative ligand binding by bovine phenol sulfotransferase.
PG  - 93-105
AB  - Although several phenol sulfotransferases (PSTs) that metabolize hormones and 
      xenobiotics have been purified and examined by steady state kinetic methods, 
      little is known about ligand binding and subunit interactions in these enzymes. 
      Inhibition of a purified recombinant homodimeric bovine PST by 
      2,6-dichloro-4-nitrophenol (DCNP) and pentachlorophenol (PCP) displayed very 
      sharp titration curves that required modeling with Hill equations with slope 
      factors of 2 and 3, respectively. This observation suggested positive cooperative 
      ligand binding during catalytic turnover. The binding of PCP was also monitored 
      by intrinsic protein fluorescence, which was quenched up to 36% upon saturation 
      with the inhibitor. In the absence of 3'-phosphoadenosine-5'-phosphosulfate 
      (PAPS), quenching curves were fit with the Hill equation and an interaction 
      factor of 1. In contrast, inclusion of PAPS increased the association of PCP and 
      resulted in positive cooperative binding with an interaction factor of 1.6-1.9. 
      Whereas adenosine-3',5'-diphosphate (PAP) also facilitated cooperative binding of 
      PCP, adenosine-5'-monophosphate (AMP) was not effective. This correlated to 
      inhibition of PST by PAP, whereas AMP was not inhibitory up to 1 mM. Therefore, 
      occupation of the PST nucleotide binding site(s) facilitates a subunit 
      interaction that can promote subsequent binding of phenolic ligands.
FAU - Beckmann, J D
AU  - Beckmann JD
AD  - Department of Biochemistry, Alma College, MI 48801, USA.
FAU - Henry, T
AU  - Henry T
FAU - Ulphani, J
AU  - Ulphani J
FAU - Lee, P
AU  - Lee P
LA  - eng
GR  - R01 CA55176/CA/NCI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - Ireland
TA  - Chem Biol Interact
JT  - Chemico-biological interactions
JID - 0227276
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Ligands)
RN  - 0 (Nucleotides)
RN  - 0 (Phenols)
RN  - 0 (Recombinant Proteins)
RN  - D9BSU0SE4T (Pentachlorophenol)
RN  - EC 2.8.2.1 (Arylsulfotransferase)
SB  - IM
EIN - Chem Biol Interact 1998 Jul 24;114(3):225-6
MH  - Animals
MH  - Arylsulfotransferase/antagonists & inhibitors/*metabolism
MH  - Binding, Competitive
MH  - Cattle
MH  - Dimerization
MH  - Enzyme Inhibitors/metabolism/pharmacology
MH  - Kinetics
MH  - Ligands
MH  - Nucleotides/pharmacology
MH  - Pentachlorophenol/metabolism/pharmacology
MH  - Phenols/metabolism/pharmacology
MH  - Recombinant Proteins/metabolism
EDAT- 1998/05/05 00:00
MHDA- 1998/05/05 00:01
CRDT- 1998/05/05 00:00
PHST- 1998/05/05 00:00 [pubmed]
PHST- 1998/05/05 00:01 [medline]
PHST- 1998/05/05 00:00 [entrez]
AID - S0009-2797(97)00123-3 [pii]
AID - 10.1016/s0009-2797(97)00123-3 [doi]
PST - ppublish
SO  - Chem Biol Interact. 1998 Feb 20;109(1-3):93-105. doi: 
      10.1016/s0009-2797(97)00123-3.