Comparison of the natural variation of Tripeptidyl peptidase II activity in blood samples among healthy subjects
Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
Tripeptidyl peptidase II (TPPII) is a very large enzyme complex with a molecular weight of 5-6MDa and it has broad substrate specificity. It is located in the cytosol in most eukaryotic cells. TPPII which is an amino peptidase has exopeptidase activity, it removes tripeptides from the free N-terminus of oligopeptides and it is acting downstream of the proteasome. TPPII participates in a number of important processes in the cell: protein degradation, antigen presentation and apoptosis. In some tumor cells an increased expression of TPPII has been found which raise the question if TPPII can be used as a tumor marker in blood. The aim of this study was to compare the natural variation of the enzyme activity in blood samples among healthy subjects and also to see if the specific activity changed dependent on how the samples were stored after sampling. To do this an activity assay was used to measure the TPPII enzyme activity and the method of Bradford. Western blot was used to ensure that the right product, TPPII protein was detected. Finally qPCR was used to evaluate the feasibility of detecting TPPII mRNA in blood samples and to determine if mRNA levels correlated to the TPPII protein amount. The result showed a variation in enzyme activity among healthy subjects, a high activity in erythrocyte fractions compared to plasma and leukocyte fractions and also that storing the samples as lysate in -80C gave the least change in relative specific activity in comparison to the fresh blood cell fractions.
Place, publisher, year, edition, pages
2011. , 25 p.
TPPII, tumor marker, exopeptidase, protein degradation
Other Basic Medicine
IdentifiersURN: urn:nbn:se:uu:diva-160066OAI: oai:DiVA.org:uu-160066DiVA: diva2:448025