CFP10 discriminates between nonacetylated and acetylated ESAT-6 of Mycobacterium tuberculosis by differential interaction.
ESAT-6 (the 6 kDa early secreted antigenic target) protein species in short-term culture filtrate of Mycobacterium tuberculosis were separated in a 4-5 narrow range pI gradient two-dimensional gel electrophoresis (2-DE). Eight ESAT-6 protein species were analyzed in detail by peptide mass fingerprinting matrix-assisted laser desorption/ionization-mass spectrometry as well as by electrospray ionization-tandem mass spectrometry. An N-terminal Thr acetylation was identified in four species and a C-terminal truncation was identified in two species. In 2-DE blot overlay assays, the recombinant 10 kDa culture filtrate protein (CFP10) discriminated N-terminal acetylated and nonacetylated ESAT-6 by differential interaction, whereas removal of the C-terminal 11 residues of ESAT-6 had no effects thereon. This example shows that the access to the protein species level can be a prerequisite to understand regulation of protein-protein interaction.
Okkels
Limei Meng
LM
Department of Infectious Disease Immunology, Statens Serum Institut, Copenhagen, Denmark.
Müller
Eva-Christina
EC
Schmid
Monika
M
Rosenkrands
Ida
I
Kaufmann
Stefan H E
SH
Andersen
Peter
P
Jungblut
Peter R
PR
D000107:Acetylation; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C117940:CFP-10 protein, Mycobacterium tuberculosis; C093276:ESAT-6 protein, Mycobacterium tuberculosis