Differential expression of semicrabazide-sensitive amine oxidase (SSAO) in human umbilical arterial tissue, E.coli BL21, HEK and HUAEC

Semicarbazide-sensitive amine oxidase (SSAO) is multifunctional enzyme which is highly express in vasculature, smooth muscle and adipose tissues. Clinical and experimental studies suggest that increased activity and the catalytic product of deamination may be toxic and cause the tissue damage. Correlation between the SSAO activity and severity of different serious pathological condition such as Diabetes, Alzheimer's disease and atherosclerosis have been widely reported but pathophysiological meaning of this enzyme is not yet discovered. Therefore, research related to SSAO as therapeutic objective are becoming more important. We present liquid chromatography electrospray ionization mass spectrometry (LC-MS/MS) based comparative enzymatic activity and expression study in human umbilical tissue, universal recombinant expression system E.coli; commonly used cell line i.e., human embryonic kidney cell (HEK) and naturally SSAO expressive primary vascular cell line i.e., human umbilical arterial endothelial cell (HUAEC). Our results indicate that HEK:SSAO is best model among these while the second most abundant activity was observed in E.coli BL21:SSAO, with a rough estimation HEK:SSAO shows two to three fold higher activity than HUAEC. The concept of comparison provides new insight on this enzyme expression. Our models also open new possibilities for the evaluation of potential compounds that could modify SSAO activity for therapeutic determinations.