Environmental Engineering Reference
In-Depth Information
15.3.8.2 Applications in Microbiology
Protein expression profile of a single sample under different circumstances can be
determined by the use of 2-DE. This profile can be compared to that of a control
condition to examine the changes in protein expression of microbial/bacterial cells
in response to a foreign stimulus resulting from chemical, physical or biological
changes. A set of proteins that responds specifically to a particular status of the cell
termed as a proteomic signature relates to a certain metabolic conditions such as the
redox state, proton motive force, etc. This proteomic signature can be used to
diagnose the cellular states of microbial organisms [
101
]. 2-DE has been exten-
sively employed to differentiate and classify the microbial isolates required for the
study of the molecular taxonomy and epidemiology of bacterial pathogens
[
102
]. The proteome studies have been applied for the detection of antigens
which may be used for diagnostics and vaccine candidate prediction [
103
]. 2-DE
has been applied for the characterisation of proteins, characterising protein modi-
fications, protein-protein interactions, metabolic engineering, characterisation of
mutant proteins, microbial systematics and epidemiology, and evaluation of pro-
teins involved in the toxic response [
104
].
V. cholera
is a gram-negative bacterium with two different physiological states,
in the aquatic environment and in the human small intestine. The whole cell
proteome of the
V. cholera
strain N16961 under anaerobic conditions was separated
by 2-DE and the protein spots compared with those in the aerobic environment.
Under aerobic conditions, some proteins involved in substrate transport, amino acid
metabolism and aerobic respiration were found to be abundant. The increased
abundance of these proteins related to motility was observed when the bacterium
was grown under anaerobic conditions, thus suggesting a correlation between
V. cholera
motility and pathogenesis [
105
]. This proteome analysis provided useful
information for detection of the antigens by immunoproteomics for the purpose of
vaccine development.
15.3.8.3 Clinical Chemistry
Gel electrophoresis is routinely used in clinical laboratories for screening protein
abnormalities in various biological fluids (serum, urine, CSF). The technique is
used for electrophoresis of serum, urine, CSF proteins, enzymes (ALP, LDH and
CK), lipoproteins and haemoglobin [
106
]. Serum protein electrophoresis (SPE) is a
very commonly used technique to evaluate changes in the relative concentration of
fractions and thus allow easy recognition of pathological disorders associated with
nephrotic syndrome, inflammatory reaction and hepatic diseases. Immunofixation
(IFE) with use of specific antisera allows detection of the type of M component. For
example, Bisalbuminemia as seen on the electrophoretogram as an albumin fraction
split in two can be a sign of hereditary mutation or due to pancreatitis or a drug
treatment such as high doses of beta-lactam in a patient with renal insufficiency.
