Rvs. Raju et al., EXPRESSION OF HUMAN N-MYRISTOYLTRANSFERASE IN ESCHERICHIA-COLI - COMPARISON WITH N-MYRISTOYLTRANSFERASES EXPRESSED IN DIFFERENT TISSUES, Molecular and cellular biochemistry, 155(1), 1996, pp. 69-76
Myristoyl CoA:protein N-myristoyltransferase catalyzes the addition of
myristate to the amino-terminal glycine residue of a number of eukary
otic proteins. Escherichia coli transformed with human NMT expression
construct produced high levels of N-myristoyltransferase. Using the co
mbination of ammonium sulfate precipitation, chromatography on SP-Seph
arose fast flow and fast protein liquid chromatography on Mono-S, the
enzyme was purified more than 100 fold with 40% yield. The hNMT fusion
protein exhibited an apparent molecular weight of 53 kDa on SDS-polya
crylamide gel electrophoresis. Upon cleavage by the Enterokinase [(Asp
)(4)-Lys], the hNMT exhibited an apparent molecular mass of 49 kDa wit
hout loss of catalytic activity. The hNMT activity could be greatly ac
tivated severalfold with the use of Tris, SDS, ethanol and acetonitril
e. The catalytic activity of hNMT was potently inhibited in a concentr
ation dependent manner by NIP71, a bovine brain NMT inhibitory protein
with a half maximal inhibition of 31.0 nM. The E. coli expressed hNMT
was homogeneous and showed enzyme activity.