Mycobacterium avium binds to mouse intestinal mucus aldolase.
METHODS
Mycobacterium avium complex (MAC) is known to colonize the gastrointestinal tract of human immunodeficiency virus (HIV) infected patients before causing bacteremia and disseminated disease. However, the mechanism involved in the gastrointestinal colonization is not known.


OBJECTIVE
To identify putative intestinal mucus receptors which serve as anchor for MAC colonization.


METHODS
C57BL/6 mouse intestinal mucus was subjected to single and two-dimensional electrophoresis and blotted on nitrocellulose membranes. MAC specific mucus proteins were identified by probing the mucus western blots with biotinylated proteins derived from M.avium strain 101 (MAC101).


RESULTS
Biotinylated MAC 101 proteins recognized a 39 kDa intestinal mucus glycoprotein. The protein displaying an isoelectric point (pI) of 9.0, was found to be periodate sensitive but resistant to sialidase, heparinase I and chondroitinase ABC. The internal amino acid sequence of the 39 kDa protein displayed homology with fructose-1-6-bisphosphate aldolase B (aldolase). The proclivity between MAC adhesins and aldolase was confirmed by probing rabbit muscle aldolase with MAC proteins. Furthermore, both 25 and 31 kDa MAC adhesins, superoxide dismutase and heparin binding protein, respectively, were found to bind to aldolase.


CONCLUSIONS
MAC binds to intestinal mucus aldolase, conceivably facilitating intestinal colonization of the organism.
Reddy
V M
VM
Department of Biomedical Sciences, University of Illinois College of Medicine, 1601 Parkview Avenue, Rockford, IL 61107, USA. vmreddy@uic.edu
Suleman
F G
FG
Hayworth
D A
DA
D000595:Amino Acid Sequence; D000818:Animals; D001422:Bacterial Adhesion; D046508:Culture Techniques; D005634:Fructose-Bisphosphate Aldolase / Q000235:genetics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000201:enzymology / Q000382:microbiology*; D007525:Isoelectric Focusing; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009093:Mucus / Q000201:enzymology*; D015269:Mycobacterium avium Complex / Q000378:metabolism* / Q000502:physiology; D015270:Mycobacterium avium-intracellulare Infection / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid
D005634:Fructose-Bisphosphate Aldolase