F. Dellaragione et al., PURIFICATION AND CHARACTERIZATION OF RECOMBINANT HUMAN 5'-METHYLTHIOADENOSINE PHOSPHORYLASE - DEFINITE IDENTIFICATION OF CODING CDNA, Biochemical and biophysical research communications, 223(3), 1996, pp. 514-519
5'-Methylthioadenosine phosphorylase gene maps on the 9p21 chromosome,
strictly linked to the important tumor suppressor gene p16(INK4A). Ch
romosomal deletions encompassing both the phosphorylase and p16(INK4A)
genes cause the complete absence of the enzymatic activity in a large
number of tumors, thus resulting in well-defined metabolic difference
s between malignant and normal cells. Recently, the cloning of the pho
sphorylase gene has been reported on the basis of indirect evidence. I
n order to demonstrate definitely the identification of 5'-methylthioa
denosine phosphorylase gene, we have cloned the putative enzyme coding
sequence in a prokaryotic expression vector and expressed the protein
in bacteria. The recombinant phosphorylase has been purified to homog
eneity and its physicochemical, immunological and kinetic features hav
e been characterized. The results obtained allowed the conclusive demo
nstration of 5'-methylthioadenosine phosphorylase gene cloning and the
use of recombinant protein for further characterization. (C) 1996 Aca
demic Press, Inc.