Dr Salvatore Santamaria

Lecturer in Cardiovascular Science
PhD, MSc, BSc (Hons)

Academic and research departments

Department of Biochemical Sciences.


Research interests


Salvatore Santamaria, Daniel R. Martin, Xiangyi Dong, Kazuhiro Yamamoto, Suneel S. Apte, Josefin Ahnström (2021)Post-translational regulation and proteolytic activity of the metalloproteinase ADAMTS8, In: The Journal of biological chemistry297(5)101323pp. 101323-101323 Elsevier Inc

A disintegrin-like and metalloprotease domain with thrombospondin type 1 motifs (ADAMTS)8 is a secreted protease, which was recently implicated in pathogenesis of pulmonary arterial hypertension (PAH). However, the substrate repertoire of ADAMTS8 and regulation of its activity are incompletely understood. Although considered a proteoglycanase because of high sequence similarity and close phylogenetic relationship to the proteoglycan-degrading proteases ADAMTS1, 4, 5, and 15, as well as tight genetic linkage with ADAMTS15 on human chromosome 11, its aggrecanase activity was reportedly weak. Several post-translational factors are known to regulate ADAMTS proteases such as autolysis, inhibition by endogenous inhibitors, and receptor-mediated endocytosis, but their impacts on ADAMTS8 are unknown. Here, we show that ADAMTS8 undergoes autolysis at six different sites within its spacer domain. We also found that in contrast to ADAMTS4 and 5, ADAMTS8 levels were not regulated through low-density lipoprotein receptor-related protein 1 (LRP1)-mediated endocytosis. Additionally, ADAMTS8 lacked significant activity against the proteoglycans aggrecan, versican, and biglycan. Instead, we found that ADAMTS8 cleaved osteopontin, a phosphoprotein whose expression is upregulated in PAH. Multiple ADAMTS8 cleavage sites were identified using liquid chromatography–tandem mass spectrometry. Osteopontin cleavage by ADAMTS8 was efficiently inhibited by TIMP-3, an endogenous inhibitor of ADAMTS1, 4, and 5, as well as by TIMP-2, which has no previously reported inhibitory activity against other ADAMTS proteases. These differences in post-translational regulation and substrate repertoire differentiate ADAMTS8 from other family members and may help to elucidate its role in PAH.

Salvatore Santamaria (2020)Chemical Modification of Proteoglycanases with Biotin, In: S S Apte (eds.), ADAMTS Proteasespp. 113-123 Humana Press Inc

Biotinylation is a versatile technique that has been used to label proteins for a variety of applications. Under alkaline conditions, the N-hydroxylsuccinimide (NHS) ester present on the biotinylation reagent reacts with primary amines such as the side chain of lysine residues or the N-termini of proteins to yield stable amide bonds. However, the effect of biotinylation on enzyme structure and function has not been generally appreciated. In this chapter, I describe specific issues involving biotinylation of proteoglycanases (e.g., ADAMTS-1, -4, and -5). Taking ADAMTS-5 as an example, I show how high incorporation of biotin molecules causes a decrease in aggrecanase activity, most likely by disrupting exosites present in the cysteine-rich and spacer domains. Such an effect is not evident when enzymatic activity is measured with synthetic peptides, since exosites are not strictly required for peptidolytic activity. Therefore, extreme care must be taken when labeling proteoglycanases and the appropriate enzyme/biotin ratio must be determined experimentally for each enzyme.

Salvatore Santamaria, Rens de Groot (2020)ADAMTS proteases in cardiovascular physiology and disease, In: Open biology10(12)pp. 200333-200333 Royal Soc London

The a disintegrin-like and metalloproteinase with thrombospondin motif (ADAMTS) family comprises 19 proteases that regulate the structure and function of extracellular proteins in the extracellular matrix and blood. The best characterized cardiovascular role is that of ADAMTS-13 in blood. Moderately low ADAMTS-13 levels increase the risk of ischeamic stroke and very low levels (less than 10%) can cause thrombotic thrombocytopenic purpura (TTP). Recombinant ADAMTS-13 is currently in clinical trials for treatment of TTP. Recently, new cardiovascular roles for ADAMTS proteases have been discovered. Several ADAMTS family members are important in the development of blood vessels and the heart, especially the valves. A number of studies have also investigated the potential role of ADAMTS-1, -4 and -5 in cardiovascular disease. They cleave proteoglycans such as versican, which represent major structural components of the arteries. ADAMTS-7 and -8 are attracting considerable interest owing to their implication in atherosclerosis and pulmonary arterial hypertension, respectively. Mutations in the ADAMTS19 gene cause progressive heart valve disease and missense variants in ADAMTS6 are associated with cardiac conduction. In this review, we discuss in detail the evidence for these and other cardiovascular roles of ADAMTS family members, their proteolytic substrates and the potential molecular mechanisms involved.