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A plasmodium protein kinase that is developmentally regulated, stimulated by spermine, and inhibited by quercetin
Author(s) -
Wiser Mark F.,
Eaton John W.,
Sheppard J.R.
Publication year - 1983
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240210407
Subject(s) - phosvitin , protein kinase a , casein kinase 2 , cyclin dependent kinase 2 , biochemistry , mitogen activated protein kinase kinase , casein kinase 1 , c raf , kinase , biology , microbiology and biotechnology , cyclin dependent kinase 9 , map3k7 , spermine , protein kinase r , cyclin dependent kinase 7 , cgmp dependent protein kinase , map2k7 , map kinase kinase kinase , enzyme
Plasmodium berghei–infected murine red cells possess protein kinase activity that is associated with the isolated parasites. Schizonts contain significantly higher levels of this protein kinase than the more immature forms, suggesting a relationship between this enzyme activity and parasite development. Partially purified protein kinase has a K m for ATP of ∼30 μM, whereas the K m for GTP is ∼300 μM and the substrate preference is phosvitin > casein > > histone > protamine. The Mg 2+ optimum is 10–20 mM, and the protein kinase activity is stimulated by the polyamines spermine and spermidine. The flavone, quercetin, inhibits the protein kinase activity in a competitive manner with' respect to ATP (Ki ∼3 μM), and P chabaudi also has a very similarly regulated protein kinase. Protein kinases from both species are very similar to the type I casein kinase.