Biochemical Study of Dipeptidylpeptidase-4 from Normal Human Serum | ||
Rafidain Journal of Science | ||
Article 15, Volume 27, Issue 1, March 2018, Pages 123-132 PDF (740.7 K) | ||
DOI: 10.33899/rjs.2018.143951 | ||
Authors | ||
Tareq Y. Ahmad; Fadwa KH. Tawfeeq; Safaa A. AL-Ameen | ||
Abstract | ||
The research includes partial purification of dipeptidylpeptidase-4 (DPP-4) from serum of normal person aging 14 years in Mosul city. Gel filtration of dialysate precipitate produced by 50% ammonium sulphate saturation has given two major proteinous components. One of them (peak A) possesses a high DPP-4 activity using sephedex G-100. The apparent molecular weight of the isolated DPP-4 was 176.6 KD. High performance liquid chromatography HPLC revealed a single peak à at retention time 5.829 min by application the top of peak A which was isolated from gel filtration. Maximum activity of DPP-4 was obtained using 0.1 M Tris-HCl buffer at pH 8, 40°C, 4 mM of gly-pro-p-nitroanilide hydrochloride as a substrate. The concentration 0.35 mg/ml partially purified DPP-4 was used for next experiments. Maximum velocity (Vmax) was 50 μM according to Line Weaver-Burk plot while Michaelis–Menten constant (Km) was 0.5 mM. Mercuric chloride and strontium chloride hexahydrate at 5 mM revealed maximum inhibitory effect of DPP4 activity by 30.2% and 42.9% respectively. | ||
Keywords | ||
Dipeptidylpeptidase; inhibitors; Gel filtration; High performance liquid chromatography | ||
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