Biology Reference
In-Depth Information
proteins and proteins of unknown function. Hyperosmotic stress and salt stress were perceived as
different stimuli. Hyperosmotic stress caused the induction of certain specifi c gene products like
3-keto acyl-carrier protein reductase and rare lipoprotein A. However, there were some common gene
products belonging to the category of heat shock proteins and the enzymes for the synthesis of GG
induced in both hyperosmotic stress and salt-stress. Marin
et al
. (2004) investigated genome-wide
expression of genes to salt stress by DNA microarray technique and compared these to changes in
Figure 6:
A general proteomic workfl ow. The main steps are, cell culture, protein extraction (liquid nitrogen freezing and
cracking), sample fractionation (traditional 2DE and gel-free chromatography method), mass spectrometer analysis and
protein quantitation and identifi cation. Quantitation using 2DE is densitometry based and implemented with appropriate
software (e.g. PD QUEST®, SameSpots®), but can also be undertaken on the mass spectrometer, relying on abundance of
peptide peaks. Identifi cation occurs with database search software (based on peptide mass fi ngerprint or sequence analysis).
Proteins are commonly digested using trypsin: indicate essential salt removal stages. RCDC® - protein quantitation assay kit,
IEF- isoelectric focusing, HPLC- High Performance Liquid Chromatography, SCX- Strong Cation Exchange. With the kind
permission of C. A. Biggs,
Biological and Environmental Systems Group, Department of Chemical and Process Engineering,
The University of Sheffi eld, Mappin Street, Sheffi eld, S1 3JD, UK [Pandhal
et al
. (2008)
Saline Systems
4:
1; doi:10.1186/1746-
1448-4-1].
