Foetal growth is a result of a complex net of processes, requiring coordination within the maternal, placental, and foetal compartments, the imbalance or lack of which may lead to intrauterine growth restriction (IUGR). IUGR is the major cause of perinatal morbidity and mortality, and is also related to enhanced morbidity and metabolic abnormalities later in life. In the present study, the protein profiles of umbilical cord serum (UCS) and amniotic fluid (AF) of ten IUGR and ten appropriate for gestational age newborns have been analysed by 2-DE, and nanoHPLC-Chip/MS technology. A total of 18 and 13 spots were found to be differentially expressed (p<0.01) in UCS and AF respectively. The unique differentially expressed proteins identified by MS/MS analysis were 14 in UCS, and 11 in AF samples. Protein gene ontology classification indicate that 21% of proteins are involved in inflammatory response, 20% in immune response, while a smaller proportion are related to transport, blood pressure, and coagulation. These results support the conclusion that the IUGR condition alters the expression of proteins involved in the coagulation process, immune mechanisms, blood pressure and iron and copper homeostasis control, offering a new insight into IUGR pathogenesis.

It is esteemed that 2-4% of eukaryotic genes are associated with kinases and phosphatases (there are about 500 kinase and 100 phosphatase genes in the human genome) [Manning et al., 2002; Twyman, 2004; Venter et al., 2001]. Around 100,000 phosphorylation sites may exist in the human proteome, the majority of which are presently unknown [H. Zhang et al., 2002]. The importance of studying the phosphorylation was marked by the success of the www.intechopen.com Protein Purification 190 cancer drug Gleevec, the first to inhibit a specific kinase, which gave definitely an impulse to the research on kinases and their substrates as potential drug targets [Manning et al., 2002]. The comprehensive analysis of the protein phosphorylation should include: identification of phosphorylated proteins and of their sites of phosphorylation, how these phosphorylations modify the biological activity of the protein and kinases and phosphatases involved in the process.