N-myristoyl-transferase activity in cancer cells. Solubilization, specificity and enzymatic inhibition of a N-myristoyl transferase from L1210 microsomes.
The activity catalyzed by N-myristoyl transferase (NMT) is described for the first time in microsome-rich fractions from the murine leukemia cell line L1210, rat brain and mouse liver as biological sources. The enzyme from each source can accommodate various types of proteins (protein kinase A, virus structural gag protein or pp60src) as modelized by the use of their N-terminal derived peptides (GNAAAARR, GQTVTTPL and GSSKSKPKDP, respectively). As for some other types of membrane-bound enzymes, NMT activity can be enhanced by pretreatment with various types of detergents, amongst which Triton 770 and deoxycholate were the most potent. Further experiments on the L1210 microsome-rich fractions demonstrate that these two detergents were able to solubilize the microsomal enzyme, without modifying its substrate specificity. Finally, three compounds described in the literature to be inhibitors of NMT activity from other sources were tested for L1210 microsome-associated activity. None of them show any significant potency in inhibiting this activity. A new compound, myristoylphenylalanine, shows a slightly better inhibitory effect on the L1210 microsomal activity than the reference compounds with a median inhibitory concentration (IC50) of 0.2 mM.
Departement de Cancerologie Experimentale, Institut de Recherches SERVIER, Suresnes, France.
J A
JA
Boutin
J P
JP
Clarenc
G
G
Ferry
A P
AP
Ernould
G
G
Remond
M
M
Vincent
G
G
Atassi
D000217:Acyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000201:enzymology / Q000648:ultrastructure; D002851:Chromatography, High Pressure Liquid; D003902:Detergents / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D007939:Leukemia L1210 / Q000201:enzymology*; D051379:Mice; D008861:Microsomes / Q000201:enzymology*; D008862:Microsomes, Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D051381:Rats; D012995:Solubility; D013379:Substrate Specificity; D014407:Tumor Cells, Cultured
D003902:Detergents; D000217:Acyltransferases; C050480:glycylpeptide N-tetradecanoyltransferase