Chemistry Reference
In-Depth Information
often, a reducing agent such as sodium cyanoborohydride for following product
stabilization.
embryoblast
Cells of the blastocyst that give rise to the embryo.
enantiopeptide
A peptide or peptide analog synthesized exclusively with
D
- amino acids.
endoplasmic reticulum- associated degradation (ERAD)
An activity that regulates (glyco)protein availability for the extracellular space. It is
the fi nal effector phase of quality control within the secretory pathway. It routes
inactive, dead-end folding states and excess of non-assembled subunits of oligo-
meric proteins to proteasomal annihilation after their marking with ubiquitin, a
process preceded by sensing the deviation to initiate disposal. Herein,
N
- glycans
effectively signal protein- folding states.
enthalpy of binding
The enthalpy change (
H
) accompanying the binding process. It is equal to the
heat absorbed or released in the process at constant pressure. Protein-carbohydrate
interactions are typically exothermic.
Δ
entropy of binding
The entropy change (
S
) in a binding process. Entropy is a measure of the disorder
of a system. Binding of carbohydrates by proteins typically implies a decrease in
entropy that opposes complex formation.
Δ
enzyme inhibitor
An agent that binds to an enzyme and inhibits its activity.
epididymis
A complex tubular structure attached to the testis that provides sites for sperm
maturation and storage.
epimery
A special form of isomery for monosaccharides. They have more than one asym-
metric centre. The change of confi guration at only one site results in isomers
called epimers. For instance, the pair
D
- glucose and
D
- galactose, which differ only
in the confi guration of the hydroxy group at C4, consists of epimers. Change at
the anomeric centre at C1 is excluded, this form of isomery being referred to as
anomery.
epitope
Antigenic determinant specifi cally recognized by antibodies or antigen receptors
(
see also
hapten)
