Chemistry Reference
In-Depth Information
lectin subtypes, e.g., C- type lectin - like, I - type or
- trefoil domains. Lectin domains
have different, characteristic protein folds that bind sugars by different
mechanisms.
β
lectin microarray
A method for glycan profi ling, by spotting a series of lectins with distinct sugar-
binding specifi city on a microarray platform ready for interaction with labeled
glycans. Signal read-out aids structural characterization of the studied glycan or
cells.
leukocyte
Large white cell of the immune system that defends the body against both infec-
tious disease and foreign materials.
ligand
A substance that is able to bind to and form a complex with a biomolecule to serve
a biological function by the interaction (Latin:
ligare
= to bind).
lipid raft
See
glycosphingolipid microdomain.
lipopolysaccharide
Lipid-containing polysaccharides of the cell wall of Gram-negative bacteria. The
basic units are a diglucosamine- diphosphate with amide - and ester - bound
β
hydroxy - myristic acid (lipid A), an inner core glycan including 2 - keto - 3 - deoxy -
D
-
manno-octulosonic acid (Kdo) and heptose, as well as a head part of about 40 sugar
moieties. It has a direct role in pathogenesis of infection by Gram-negative bacteria
(septicemia) and is a potent and pleiotropic activator of immune cells. The complex
with proteins on the cell is referred to as endotoxin.
lysosomal storage disease
A group of human genetic disorders characterized by excessive lysosomal accu-
mulation and excretion of incompletely degraded GAG (mucopolysaccharidoses)
or glycosphingolipids (sphingolipidoses;
see also
glycosphingolipid storage
disorders), resulting from a defi ciency of one or more lysosomal glycosidases
responsible for the degradation of dermatan and/or heparan sulfates or
glycosphingolipids.
m
major histocompatibility complex (MHC)
Glycoproteins expressed on the cell surface, encoded by a highly polymorphic gene
cluster, that function in T lymphocyte-mediated immune responses and present
peptides either of self antigens or foreign antigens to T lymphocytes. Three classes
of MHC molecules exist: MHC class I proteins present peptides to cytotoxic CD8
+
T lymphocytes, MHC class II proteins present peptides to CD4
+
T helper lympho-
