Chemistry Reference
In-Depth Information
i
infl ammation
The cooperative response of the immune and vascular systems to injury caused
by invading pathogens, damaged or malignant cells, irritating chemicals or physi-
cal agents.
integrin
A member of a family of dimeric plasma membrane glycoproteins that mediate
cell attachment to the extracellular matrix and that are implicated in cell adhesion
and migration. They bind (glyco)proteins such as fi bronectin and act as ligands
for lectins via their glycan part.
isoelectric focusing
Electrophoresis technique that separates molecules by their difference in their
isoelectric points, i.e., the pH at which a specifi c protein carries no net charge. Prac-
tical for detecting low-level sialylation in congenital disorders of glycosylation.
isothermal titration calorimetry (ITC)
A technique used to directly measure the heat released during a chemical reaction,
triggered when mixing the reaction partners. ITC is frequently used to characterize
the thermodynamics of protein-ligand interactions, to obtain the Gibbs free energy
(
Δ
G) and enthalpic/entropic contributions.
isozyme
Enzymes encoded by different genes but catalyzing the same chemical reaction.
These enzymes display different kinetic parameters, different regulatory proper-
ties, or different expression patterns.
l
L1
A member of the immunoglobulin superfamily similar to the neural cell adhesion
molecule but lacking polysialic acid chains.
lectin
A protein or glycoprotein that binds to carbohydrates (mono-, oligo-, or polysac-
charides or glycosides). Carbohydrate-binding antibodies, enzymes that act on
carbohydrates and sensor or carrier proteins for free mono- or oligosaccharides
are excluded from the class of lectins by defi nition. Many lectins agglutinate cells.
Therefore, the terms agglutinin, hemagglutinin (if red blood cells are agglutinated)
or phytohemagglutinin (if the lectin originates from plant material) are often
used.
lectin domain
Protein domain capable of binding sugar without enzymatic activity. There
are several different types of lectin domains, corresponding to the different
