PMID- 22483752
OWN - NLM
STAT- MEDLINE
DCOM- 20120622
LR  - 20120501
IS  - 1090-2104 (Electronic)
IS  - 0006-291X (Linking)
VI  - 421
IP  - 1
DP  - 2012 Apr 27
TI  - Identification and characterization of a novel Ribose 5-phosphate isomerase B 
      from Leishmania donovani.
PG  - 51-6
LID - 10.1016/j.bbrc.2012.03.107 [doi]
AB  - Leishmaniasis is a group of tropical diseases caused by protozoan parasites of 
      the genus Leishmania. Due to the emergence of resistance to the available 
      antileishmanial drugs there is an immediate need to identify molecular targets on 
      which to base future treatment strategies. Ribose 5-phosphate isomerase (Rpi; EC 
      5.3.1.6) is a key enzyme of the pentose phosphate pathway (PPP) which catalyses 
      the reversible aldose-ketose isomerization between Ribose 5-phosphate (R5P) and 
      Ribulose 5-phosphate (Ru5P). It exists in two isoforms A and B. These two are 
      completely unrelated enzymes catalyzing the same reaction. Analysis of the 
      Leishmania infantum genome revealed that though the RpiB gene is present, RpiA 
      homologs are completely absent. An absence of RpiBs in the genomes of higher 
      animals makes this enzyme a possible target for the chemotherapy of 
      Leishmaniasis. In this paper, we report for the first time the presence of B 
      isoform of the Rpi enzyme in Leishmania donovani (LdRpiB) by cloning and 
      molecular characterization of the enzyme. An amplified L. donovani RpiB gene is 
      519 bp and encodes for a putative 172 amino acid protein with a molecular mass of 
       approximately 19 kDa. An  approximately 19 kDa protein with poly-His tag at the C-terminal end was obtained 
      by heterologous expression of LdRpiB in Escherichia coli. The recombinant form of 
      RpiB was obtained in soluble and active form. The LdRpiB exists as a dimer of 
      dimers i.e. the tetramer form. The polyclonal antibody against Trypanosoma cruzi 
      RpiB could detect a band of  approximately 19 kDa with the purified recombinant RpiB as well as 
      native RpiB from the L. donovani promastigotes. Recombinant RpiB obeys the 
      classical Michaelis-Menten kinetics utilizing R5P as the substrate with a K(m) 
      value of 2.4+/-0.6 mM and K(cat) value of 30+/-5.2 s(-1). Our study confirms the 
      presence of Ribose 5-phosphate isomerase B in L. donovani and provides functional 
      characterization of RpiB for further validating it as a potential drug target.
CI  - Copyright (c) 2012 Elsevier Inc. All rights reserved.
FAU - Kaur, Preet Kamal
AU  - Kaur PK
AD  - Department of Biotechnology, National Institute of Pharmaceutical Education and 
      Research, SAS Nagar, Mohali 160 062, Punjab, India.
FAU - Dinesh, Neeradi
AU  - Dinesh N
FAU - Soumya, Neelagiri
AU  - Soumya N
FAU - Babu, Neerupudi Kishore
AU  - Babu NK
FAU - Singh, Sushma
AU  - Singh S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120329
PL  - United States
TA  - Biochem Biophys Res Commun
JT  - Biochemical and biophysical research communications
JID - 0372516
RN  - 0 (Protozoan Proteins)
RN  - 0 (Recombinant Proteins)
RN  - EC 5.3.1.- (Aldose-Ketose Isomerases)
RN  - EC 5.3.1.6 (ribosephosphate isomerase)
SB  - IM
MH  - Aldose-Ketose Isomerases/*chemistry/genetics/isolation & purification
MH  - Amino Acid Sequence
MH  - Kinetics
MH  - Leishmania donovani/*enzymology
MH  - Molecular Sequence Data
MH  - Molecular Weight
MH  - Protozoan Proteins/*chemistry/genetics/isolation & purification
MH  - Recombinant Proteins/chemistry/classification/genetics/isolation & purification
EDAT- 2012/04/10 06:00
MHDA- 2012/06/23 06:00
CRDT- 2012/04/10 06:00
PHST- 2012/03/14 00:00 [received]
PHST- 2012/03/21 00:00 [accepted]
PHST- 2012/04/10 06:00 [entrez]
PHST- 2012/04/10 06:00 [pubmed]
PHST- 2012/06/23 06:00 [medline]
AID - S0006-291X(12)00576-1 [pii]
AID - 10.1016/j.bbrc.2012.03.107 [doi]
PST - ppublish
SO  - Biochem Biophys Res Commun. 2012 Apr 27;421(1):51-6. doi: 
      10.1016/j.bbrc.2012.03.107. Epub 2012 Mar 29.