Purification and characterization of a group of five novel peptide serine protease inhibitors from ovaries of the desert locust, Schistocerca gregaria

FEBS Letters

Schoofs, Liliane¹  Van Beeumen, Jozef³  Devreese, Bart³  De Loof, Arnold¹  Chiou, Shean-Jaw¹  Wataleb, Said²  Vanden Broeck, Jozef¹  Hamdaoui, Ahmed² 

[1] Zoological Institute, Katholieke Universiteit Leuven, Naamsestraat 59, B-3000 Leuven, Belgium;Faculty of Science Semlalia, Université Cadi Ayyad, Avenue Molay Abdellaah, B.P. S/15, Marrakech, Morocco;Laboratory for Protein Biochemistry and Protein Engineering, RUG, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium

关键词: Serine protease inhibitor;    Schistocerca gregaria;    Chymotrypsin;    Trypsin;    Elastase;    Insect ovary;   

DOI  :  10.1016/S0014-5793(97)01585-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The ovary of the desert locust, Schistocerca gregaria, contains multiple inhibitors of serine proteases. Five serine protease inhibitors, designated SGPI-1–5 (Schistocerca gregaria protease inhibitors) were purified from methanolic extracts of mature ovaries and analyzed by mass spectrometry and amino acid sequencing. The revealed primary structures display amino acid similarities and are related to the serine protease inhibitors identified in the hemolymph of Locusta migratoria. All inhibitors show an in vitro inhibiting activity towards α-chymotrypsin. In addition, SGPI-1 displays in vitro inhibiting activity towards trypsin, and SGPI-2 is a potent pancreatic elastase inhibitor. Differences in inhibitory specificities towards the locust endogenous serine proteases can be readily attributed to the amino acid sequence within the active region and also to amino acid residues beyond the P1-P′1 bond. A difference in one or two amino acid residues around the reactive sites results in considerable alteration of the inhibitory specificity. The temporal and spatial distribution of SGPI-1–5 was studied by RP-HPLC analysis. All inhibitors occur in hemolymph, ovaries, testes and fat body of adults but are absent in the gut. They are also present in larval hemolymph and fat body. An antibody raised against SGPI-2 shows positive immunostaining in the ovarian follicle cells.

【 授权许可】

Unknown