| 1. |
- Chen, Xingchen, et al.
(författare)
-
Potent, multi-target serine protease inhibition achieved by a simplified beta-sheet motif
- 2019
-
Ingår i: PLOS ONE. - : Public Library Science. - 1932-6203. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- Engagement of an extended beta-sheet is a common substrate/inhibitor interaction at the active site of serine proteases and is an important feature of Laskowski mechanism inhibitors that present a substrate-like loop to a target protease. This loop is cleaved but subsequently relegated forming a stable inhibitor/protease complex. Laskowski inhibitors are ubiquitous in nature and are used extensively in serine protease inhibitor design. However, most studies concentrate on introducing new sidechain interactions rather than the direct contributions of the substrate-like beta-sheet to enzyme inhibition. Here we report the crystal structure of an simplified beta-sheet inhibitory motif within the Sunflower Trypsin Inhibitor (SFTI) in complex with trypsin. We show that the intramolecular hydrogen bond network of this SFTI variant (SFTI-TCTR) engages the inhibitor sidechains that would normally interact with a target protease, giving mainchain interactions a more prominent role in complex formation. Despite having reduced sidechain interactions, this SFTI variant is remarkably potent and inhibits a diverse range of serine proteases. Crystal structural analysis and molecular modelling of SFTI-TCTR complexes again indicates an interface dominated by beta-sheet interactions, highlighting the importance of this motif and the adaptability of SFTI as a scaffold for inhibitor design.
|
|
| 2. |
- de Veer, Simon J., et al.
(författare)
-
Engineered protease inhibitors based on sunflower trypsin inhibitor-1 (SFTI-1) provide insights into the role of sequence and conformation in Laskowski mechanism inhibition
- 2015
-
Ingår i: Biochemical Journal. - 0264-6021 .- 1470-8728. ; 469:2, s. 243-253
-
Tidskriftsartikel (refereegranskat)abstract
- Laskowski inhibitors regulate serine proteases by an intriguing mode of action that involves deceiving the protease into synthesizing a peptide bond. Studies exploring naturally occurring Laskowski inhibitors have uncovered several structural features that convey the inhibitor's resistance to hydrolysis and exceptional binding affinity. However, in the context of Laskowski inhibitor engineering, the way that various modifications intended to fine-tune an inhibitor's potency and selectivity impact on its association and dissociation rates remains unclear. This information is important as Laskowski inhibitors are becoming increasingly used as design templates to develop new protease inhibitors for pharmaceutical applications. In this study, we used the cyclic peptide, sunflower trypsin inhibitor-1 (SFTI-1), as a model system to explore how the inhibitor's sequence and structure relate to its binding kinetics and function. Using enzyme assays, MD simulations and NMR spectroscopy to study SFTI variants with diverse sequence and backbone modifications, we show that the geometry of the binding loop mainly influences the inhibitor's potency by modulating the association rate, such that variants lacking a favourable conformation show dramatic losses in activity. Additionally, we show that the inhibitor's sequence (including both the binding loop and its scaffolding) influences its potency and selectivity by modulating both the association and the dissociation rates. These findings provide new insights into protease inhibitor function and design that we apply by engineering novel inhibitors for classical serine proteases, trypsin and chymotrypsin and two kallikrein-related peptidases (KLK5 and KLK14) that are implicated in various cancers and skin diseases.
|
|
| 3. |
- de Veer, Simon J., et al.
(författare)
-
Exploring the active site binding specificity of kallikrein-related peptidase 5 (KLK5) guides the design of new peptide substrates and inhibitors
- 2016
-
Ingår i: Biological chemistry (Print). - : Walter de Gruyter GmbH. - 1431-6730 .- 1437-4315. ; 397:12, s. 1237-1249
-
Tidskriftsartikel (refereegranskat)abstract
- Kallikrein-related peptidase 5 (KLK5) is a promising therapeutic target in several skin diseases, including Netherton syndrome, and is emerging as a potential target in various cancers. In this study, we used a sparse matrix library of 125 individually synthesized peptide substrates to characterize the binding specificity of KLK5. The sequences most favored by KLK5 were GRSR, YRSR and GRNR, and we identified sequence-specific interactions involving the peptide N-terminus by analyzing kinetic constants (k(cat) and K-M) and performing molecular dynamics simulations. KLK5 inhibitors were subsequently engineered by substituting substrate sequences into the binding loop (P1, P2 and P4 residues) of sunflower trypsin inhibitor-1 (SFTI-1). These inhibitors were effective against KLK5 but showed limited selectivity, and performing a further substitution at P2' led to the design of a new variant that displayed improved activity against KLK5 (K-i = 4.2 +/- 0.2 nm), weak activity against KLK7 and 12-fold selectivity over KLK14. Collectively, these findings provide new insight into the design of highly favored binding sequences for KLK5 and reveal several opportunities for modulating inhibitor selectivity over closely related proteases that will be useful for future studies aiming to develop therapeutic molecules targeting KLK5.
|
|
| 4. |
- de Veer, Simon J., et al.
(författare)
-
Selective Substrates and Inhibitors for Kallikrein-Related Peptidase 7 (KLK7) Shed Light on KLK Proteolytic Activity in the Stratum Corneum
- 2017
-
Ingår i: Journal of Investigative Dermatology. - : Elsevier BV. - 0022-202X .- 1523-1747. ; 137:2, s. 430-439
-
Tidskriftsartikel (refereegranskat)abstract
- Proteases have pivotal roles in the skin's outermost layer, the epidermis. In the stratum corneum, serine proteases from the kallikrein-related peptidase (KLK) family have been implicated in several key homeostatic processes, including desquamation. However, the precise contribution of specific KLKs to each process remains unclear. To address this, we used a chemical biology approach and designed selective substrates and inhibitors for KLK7, the most abundant KLK protease in the stratum corneum. The resulting KLK7 inhibitor is the most potent inhibitor of this protease reported to date (K-i = 140 pM), and displays at least 1,000-fold selectivity over several proteases that are related by function (KLK5 and KLK14) or specificity (chymotrypsin). We then used substrates and inhibitors for KLK5, KLK7, and KLK14 to explore the activity of each protease in the stratum corneum using casein zymography and an ex vivo desquamation assay. These experiments provide the most detailed assessment of each KLK's contribution to corneocyte shedding in the plantar stratum corneum, revealing that inhibition of KLK7 alone is sufficient to block shedding, whereas KLK5 is also a major contributor. Collectively, these findings unveil chemical tools for studying KLK activity and demonstrate their potential for characterizing KLK biological functions in epidermal homeostasis.
|
|
