title: Dipeptidyl peptidase 4 - An important digestive peptidase in Tenebrio molitor larvae.
abstract: Dipeptidyl peptidase 4 (DPP 4) is a proline specific serine peptidase that plays an important role in different regulatory processes in mammals. In this report, we isolated and characterized a unique secreted digestive DPP 4 from the anterior midgut of a stored product pest, Tenebrio molitor larvae (TmDPP 4), with a biological function different than that of the well-studied mammalian DPP 4. The sequence of the purified enzyme was confirmed by mass-spectrometry, and was identical to the translated RNA sequence found in a gut EST database. The purified peptidase was characterized according to its localization in the midgut, and substrate specificity and inhibitor sensitivity were compared with those of human recombinant DPP 4 (rhDPP 4). The T. molitor enzyme was localized mainly in the anterior midgut of the larvae, and 81% of the activity was found in the fraction of soluble gut contents, while human DPP 4 is a membrane enzyme. TmDPP 4 was stable in the pH range 5.0-9.0, with an optimum activity at pH 7.9, similar to human DPP 4. Only specific inhibitors of serine peptidases, diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride, suppressed TmDPP 4 activity, and the specific dipeptidyl peptidase inhibitor vildagliptin was most potent. The highest rate of TmDPP 4 hydrolysis was found for the synthetic substrate Arg-Pro-pNA, while Ala-Pro-pNA was a better substrate for rhDPP 4. Related to its function in the insect midgut, TmDPP 4 efficiently hydrolyzed the wheat storage proteins gliadins, which are major dietary proteins of T. molitor.
authors.affiliation: Chemical Faculty, Lomonosov Moscow State University, Moscow 119991, Russia.
authors.forename: Valeriia F
authors.initials: VF
authors.lastname: Tereshchenkova
authors.affiliation: Chemical Faculty, Lomonosov Moscow State University, Moscow 119991, Russia.
authors.forename: Irina A
authors.initials: IA
authors.lastname: Goptar
authors.affiliation: Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119991, Russia.
authors.forename: Irina A
authors.initials: IA
authors.lastname: Kulemzina
authors.affiliation: Biological Faculty, Lomonosov Moscow State University, Moscow 119991, Russia.
authors.forename: Dmitry P
authors.initials: DP
authors.lastname: Zhuzhikov
authors.affiliation: A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia.
authors.forename: Marina V
authors.initials: MV
authors.lastname: Serebryakova
authors.affiliation: A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia.
authors.forename: Mikhail A
authors.initials: MA
authors.lastname: Belozersky
authors.affiliation: A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia.
authors.forename: Yakov E
authors.initials: YE
authors.lastname: Dunaevsky
authors.affiliation: USDA Agricultural Research Service, Center for Grain and Animal Health Research, 1515 College Ave., Manhattan, KS 66502, USA. Electronic address: bso@ksu.edu.
authors.forename: Brenda
authors.initials: B
authors.lastname: Oppert
authors.affiliation: Chemical Faculty, Lomonosov Moscow State University, Moscow 119991, Russia.
authors.forename: Irina Yu
authors.initials: IY
authors.lastname: Filippova
authors.affiliation: A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia.
authors.forename: Elena N
authors.initials: EN
authors.lastname: Elpidina
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018819:Dipeptidyl Peptidase 4 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D041981:Gastrointestinal Tract / Q000201:enzymology; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D016415:Sequence Alignment; D013712:Tenebrio / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development
chemical_list: D019476:Insect Proteins; D018819:Dipeptidyl Peptidase 4
keywords: DPP 4; Dipeptidyl peptidase 4; Insect digestive peptidases; Proline specific serine peptidase; Tenebrio molitor; Yellow mealworm