Strongly binds and inhibits lysozyme, may help bacteria survive in lysozyme-producing host cells. When overexpressed in M.tuberculosis or M.smegmatis increases resistance to hen egg white lysozyme. M.smegmatis overexpressing LprI survive better during intracellular infection of peritoneal and monocyte-derived macrophages, both of which produce lysozyme during infection; M.smegmatis does not encode this protein. Somewhat better survival is seen in human cell lines when M.smegmatis cells express both proteins from this operon, i.e. GlbN (HbN) and LprI. Homodimer. Protein is accessible to externally added trypsin and alpha-D-mannosidase. Constitutively expressed, increases in stationary phase (at protein level). mRNA levels rise nearly 50-fold during mouse macrophage infection. Part of the glbN-lprI operon. Glycosylated; alpha-D-mannosidase treatment decreases its apparent molecular weight. Glycosylation probably helps target protein to the cell surface; mutation of predicted glycosylation sites (Thr-24, Thr-28 and/or Thr-117) makes protein partially inaccesible to externally added trypsin. May also be glycosylated on other residues. Glycosylation is probably not necessary for inhibition of lysozyme. Probably essential, it cannot be deleted. In the C-terminal section; belongs to the MliC family.