Lysozyme: a brief review

Abstract

Summary Serum lysozyme (muramidase) estimation is a simple, convenient and useful laboratory investigation. A review of the literature shows that lysozyme has been implicated as an aetiological factor in various disorders, and credited with being a prognostic indicator in acute myeloid leukaemia, but these promises have not been fulfilled. This low molecular weight protein is found in the urine of some patients with renal tubular disorders, but some workers have emphasized its importance as a causal agent in hypokalaemia of acute myeloid leukaemia. Research should be concentrated on muramidase as an expression of cell functions rather than as an aetiological factor. Hypokalaemia in acute myeloid leukaemia may be caused by an unidentified substance of molecular weight similar to that of lysozyme.

Discovery, Modification and Production of T4 Lysozyme for Industrial and Medical Uses

“…In addition, an elevated serum lysozyme level could be helpful in differentiating between the types of cancer that affect blood, bone marrow and lymph nodes. However, lysozyme has been associated with other abnormalities since its activity increases in the gastric juice of patients with a peptic ulcer and in the colonic sections of patients with ulcerative colitis and regional enteritis (Mir, 1977). Elevated levels of lysozyme are also associated with certain abnormalities in humans.…”

“…Additionally, lysozymuria has been reported in various renal tubular disorders as a manifestation of the disease. Furthermore, discrepancies could be caused by differences in methods, patient populations and stages of disease (Mir, 1977). It was also reported that lysozyme is an effective agent for killing HIV in vitro (Song & Hou, 2003) …”

“…Lysozyme is a bacteriolytic enzyme that has the ability to hydrolyze glycosidic bonds of 1,4-beta-linkages between N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) in peptidoglycan (PG), which is present in the cell walls of prokaryotes (e.g., bacteria) (Mir, 1977;Akinalp et al, 2007) (Figure 1). In addition, its lytic activity has also been reported to inhibit viruses and eukaryotes, including fungi and parasites, in the absence of typical PG in their cell walls.…”

Oral candidal carriage, salivary lysozyme levels, and their relationship with CD4 count in HIV‐infected patients

“…It plays an important role in innate immunity. It was first discovered by Fleming in 1922 as a remarkable bacteriolytic element in tissues and secretions . It has been localized in serous acini and intercalated ducts of submandibular, sublingual, and minor salivary glands.…”

“…It was first discovered by Fleming in 1922 as a remarkable bacteriolytic element in tissues and secretions. 7 It has been localized in serous acini and intercalated ducts of submandibular, sublingual, and minor salivary glands. The presence of lysozyme in ductal cells could be a result of reabsorption from the saliva or filtration from the blood or surrounding tissues.…”