Dictionary > Hemolysin

Hemolysin

Definition
noun, plural: hemolysins
An agent or substance that causes hemolysis, i.e. the lysis of red blood cells resulting in the release of hemoglobin
Supplement
A hemolysin refers to any agent or substance that promotes hemolysis. It may be an exotoxin protein produced by bacteria. It may also be an antibody in which the resulting immune action involves hemolysis. Other possible hemolysins are other immunologic factors, toxins, and enzymes. A hemolysin is capable of causing lysis of the red blood cells resulting in the release of hemoglobin.
A hemolysin produced by bacteria (e.g. Staphyloccus and Streptococcus spp.) is exemplified by streptolysin. Streptococci producing exotoxic streptolysins may be grouped as alpha– or beta-. The alpha-hemolytic streptococci produce hemolysins that can cause incomplete hemolysis whereas the beta-type causes complete hemolysis of red blood cells.
Hemolysis of red blood cells can also be mediated by antibodies. Two possible mechanisms are described: (1) intravascular destruction of erythrocytes by complement lysis and (2) extravascular destruction of erythrocytes by immune cells that recognize antibody and complement bound to the erythrocyte.1
Autoimmune hemolytic anemia is an example of a rare case wherein the action of the antibodies is directed towards own red blood cells. The condition is, thus, characterized by anemia (where there is an insufficient number of erythrocytes to carry oxygen in the bloodstream).
Word origin: Greek haǐma (blood) + lysin
Variant(s):

  • haemolysin (British)

Synonym(s):

  • erythrocytolysin
  • erythrolysin
  • See also:

    Reference(s):

    1 Flegel, W. A. (2015). Pathogenesis and mechanisms of antibody-mediated hemolysis. Transfusion, 55(0), S47–S58. http://doi.org/10.1111/trf.13147


    You will also like...

    DNA - schematic
    Genetic Mutations

    This tutorial looks at the mutation at the gene level and the harm it may bring. Learn about single nucleotide polymorph..

    Gibberellins and Gibberellic Acid
    Gibberellins and Gibberellic Acid

    This tutorial describes the role of gibberellin family in plants. Find out the effects of gibberellin on plant growth an..

    Salmon jumping upstream in the river
    Lotic Communities & Animals

    A running water environment offers numerous microhabitats for many types of animals. Similar to plants, animals in lotic..

    Geological Periods
    Geological Periods

    Geological periods is a study guide that cites the different geological periods on Earth's timeline. Each has a brief ov..

    Chemical effects on plant growth and development
    Effect of Chemicals on Growth & Development in Organisms

    Plants and animals need elements, such as nitrogen, phosphorus, potassium, and magnesium for proper growth and developme..

    Non-Mendelian Inheritance
    Non-Mendelian Inheritance

    In this tutorial, find out more about certain types of inheritance that does not follow the Mendelian inheritance patter..

    Related Articles...

    No related articles found

    See all Related Topics