Mouse anti-Human STAP1 monoclonal antibody, clone 6B21

Introduction. Familial hypercholesterolemia (FH) is an autosomal dominant inherited disease characterized by elevated plasma low-density lipoprotein cholesterol (LDL-C). Targeted Next Generation Sequencing (NGS) is a new opportunity to expand the existing pathogenic variants (PVs) spectrum associated to FH. Our aim was to report a diagnostic NGS-based approach to detect variants associated to FH. Methods. We report two patients: a 48-year-old Asian woman, without known history of hypercholesterolemia and a 46-year-old Caucasian man, with childhood hypercholesterolemia. Results. An effective NGS-based pipeline, FH-Devyser kit/Amplicon Suite, beginning from sequencing to data analysis, did not identify known PVs in the LDLR, APOB, APOE, LDLRAP1, STAP1 and PCSK9 genes, but revealed two novel LDLR variants (c.1564A>T, p.Ile522Phe and c.1688C>T, p.Pro563Leu). Discussion and conclusions. This study showed that an effective NGS-based pipeline led to a definitive diagnosis in two FH families, allowing to plan their therapeutic treatment. Although the functional consequence of the two LDLR variants needs to be assessed in vitro, the in silico analysis and high preservation of the two amino acid positions observed in the LDLR protein, across different animal species, suggest that both variants are deleterious.

Plant aspartic proteinases (EC 3. 4. 23) have been associated with abiotic stress responses, but little is known about their possible involvement in biotic stress responses. Here we report the induction of an aspartic proteinase, StAP3 (Solarium tuberosum aspartic protease), in potato leaves upon infection with Phytophthora infestans and we compare its antimicrobial activity and substrate specificity whith StAP1, an aspartic protease from potato tubers previously characterized. Both the aspartic proteinase content and activity were significantly increased in leaves from a resistant cultivar (cv Pampeana) as compared to a susceptible one (cv Bintje). In vitro analysis shows that StAP3 has antimicrobial activity towards P. infestans and Fusarium solani, like StAP1 from tubers. Substrate specificity of StAP1 and StAP3 was studied, using oxidized insuline, beta-chain as substrate. Both enzymes have a common cleavage position, like other plant aspartic proteases. Additionally, StAP1 has other two cleavage positions and StAP3 was able to cleave the peptide bond Phela(24)-Phe(25), a cleavage position found in other plant APs. The induction of both StAPs (StAP1 and StAP3) in potato tubers and leaves after wounding and infection in potato resistant cultivars and their antimicrobial activity would suggest that these StAPs are involved in plant defense response. In a previous paper, StAPs antimicrobial activity was ascribed to StAPs proteolytic activity. Differences in the antimicrobial activity of StAP1 and StAP3 may be associated with the differences found in the substrate specificity between these enzymes.