Hyperglycosylation of glycopeptidolipid of Mycobacterium smegmatis under nutrient starvation: structural studies.
The presence of a polar species of glycopeptidolipid (GPL) in carbon-starved Mycobacterium smegmatis has been reported previously. In this study, the complete structure of this GPL is established with the help of MALDI-TOF (matrix assisted laser desorption/ionization time of flight) and ESI (electrospray ionization) -MS, (13)C-SEFT (spin echo Fourier transform) -NMR spectroscopy, and HPLC analysis. In the molecule, two units of a 3,4-di-O-methyl derivative of rhamnose are attached to l-alaninol via a 1-->2 linkage. Various methyl derivatives of rhamnose and 6-deoxytalose were synthesized as standards to establish this structure. The accumulation of this polar GPL in M. smegmatis is sigB dependent, as a SigB-overproducing strain of M. smegmatis shows the presence of this spot in the exponential phase, and a sigB-knockout strain of M. smegmatis does not show the presence of any polar GPLs.
Molecular Biophysics Unit, Indian Institute of Science, Bangalore-560012, India.
Raju
R
Mukherjee
TB Center, The Public Health Research Institute at the International Center for Public Health, 225 Warren Street, Newark, NJ 07103-3535, USA.
Manuel
M
Gomez
Department of Organic Chemistry, Indian Institute of Science, Bangalore-560012, India.
Narayanaswamy
N
Jayaraman
TB Center, The Public Health Research Institute at the International Center for Public Health, 225 Warren Street, Newark, NJ 07103-3535, USA.
Issar
I
Smith
Molecular Biophysics Unit, Indian Institute of Science, Bangalore-560012, India.
Dipankar
D
Chatterji
D005947:Glucose / Q000378:metabolism; D006017:Glycolipids / Q000302:isolation & purification / Q000378:metabolism*; D020102:Mycobacterium smegmatis / Q000201:enzymology / Q000378:metabolism*; D010455:Peptides / Q000302:isolation & purification / Q000378:metabolism*; D012210:Rhamnose / Q000031:analogs & derivatives / Q000737:chemistry* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D006017:Glycolipids; D010455:Peptides; D005947:Glucose; D012210:Rhamnose