Chemistry Reference
In-Depth Information
solution is continuously applied onto the lectin-bearing column and the volume
representing the elution front is measured. If the sugar binds to the lectin, the
elution front is delayed, depending on the affi nity.
K
a
can be calculated from the
elution front.
furanose
Monosaccharides consisting of a fi ve-atom ring. The ring is closed by reaction
between the aldehyde or keto group with a hydroxy group from the same molecule,
forming an inner hemiacetal or hemiketal. The term follows the name of the
simplest fi ve - membered O - containing heterocyclus, furan.
g
galactosylceramide
A glycosphingolipid containing galactose attached glycosidically to the 1-hydroxyl
of the sphingosine moiety within ceramide. Also termed cerebroside, it is a major
component of the myelin sheath. Its 3' - sulfation produces a sulfatide.
galectin
A member of a family of lectins with conserved carbohydrate recognition domain
of about 130 amino acids present in protists (fungi, sponges), invertebrates and
vertebrates, initially detected by lactose- inhibitable hemagglutination (formerly
called electrolectin, galaptin or S-type lectin).
ganglioside
A glycosphingolipid with one or more sialic acids as part of the oligosaccharide
chain, especially abundant in the central nervous system.
gene targeting
A genetic technique to inactivate an endogenous gene. This method can be used
to delete a gene, remove exons, and introduce point mutations.
Gibbs free energy of binding
The change in Gibbs free energy (
G
) coupled to the binding process. It is equal
to the energy released upon binding and determines the binding affi nity (
Δ
G
= -
RT
ln
K
, where
R
is the gas constant,
T
the absolute temperature and
K
the binding
equilibrium constant).
Δ
Δ
G
is a function of the enthalpy (
Δ
H
) and entropy (
Δ
S
)
changes associated to the process (
Δ
G
=
Δ
H
−
T
Δ
S
).
glycan
Oligo- or polysaccharide. Glycan may also be used to refer to the carbohydrate
portion of a glycoconjugate such as a glycoprotein, glycolipid, or a proteoglycan.
glycan antenna
Linear glycan chain on proteins or lipids. Branching reactions of glycosyltransfer-
ases generate new antennae, hence multivalency.
