Inhibition of bovine α-chymotrypsin by cyclic trypsin inhibitor SFTI-1 isolated from sunflower seeds and its two acyclic analogues

Zabłotna, Ewa; Kaźmierczak, Katarzyna; Jaśkiewicz, Anna; Kupryszewski, G.

doi:10.1007/bf02576875

Cited by 8 publications

(12 citation statements)

References 18 publications

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“…6 The absence of the disulfide bond in a Cys-deficient mutant was found to be significantly more important than head-to-tail cyclization in the inhibitory activity and hydrolysis rates determined for both trypsin 12 and chymotrypsin. 13 Similarly, replacing the cysteine residues with selenocysteine, and hence replacing the disulfide bond with a diselenide bond resulted in decreased activity to *30% of the disulfide containing peptide. 12 Strikingly though, substitution of the Cys residues with serine reduced trypsin inhibitory activity to 0.02%.…”

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confidence: 98%

Sunflower trypsin inhibitor‐1, proteolytic studies on a trypsin inhibitor peptide and its analogs

et al. 2010

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Sunflower trypsin inhibitor-1 (SFTI-1) is a 14 amino acid cyclic peptide from sunflower seeds, which possesses exceptionally potent trypsin-inhibitory activity, and has promise as a stable peptide-based drug template. Within its compact structure, SFTI-1 combines a head-to-tail cyclized backbone and a disulfide bond. In this study, we synthesized a range of acyclic and disulfide-deficient analogs of SFTI-1 to investigate enzyme-assisted cyclization of the peptide backbone and proteolytic degradation that occurs as a result of incubation with trypsin. Electrospray and matrix-assisted laser desorption ionization mass spectrometry allowed the characterization of a range of novel degradation products and elucidation of the time-course for cyclization and/or proteolysis. Trypsin displayed the ability to resynthesize the scissile bond(s) and hence cyclize two of the linear permutants, whereas irreversible degradation was observed for another two permutants. An interesting ring contraction mediated by trypsin was observed, supporting a role for protease catalyzed splicing as a way of increasing the combinatorial diversity of cyclic peptides in nature. Disulfide-deficient mutants were degraded within minutes, emphasizing the critical role of the cysteine bridge in maintaining proteolytic stability of SFTI-1. Overall, the study provides additional support for the proposal that naturally occurring cyclic peptides like SFTI-1 are biosynthesized by proteolytic enzymes effectively catalyzing the reverse of their normal reaction to make, rather than break peptide bonds.

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confidence: 98%

Sunflower trypsin inhibitor‐1, proteolytic studies on a trypsin inhibitor peptide and its analogs

et al. 2010

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“…However, it is a strong inhibitor of bovine a-trypsin. The determined value of the association equilibrium constant (K a ) for this analog is 3.8 Â 10 8 m À1 [8] whereas for wild SFTI-1 (5.20 Â 10 6 m À1 [18]. Recently Krzywda et al have published a crystal structure of [Nlys 5 ]SFTI-1 in complex with bovine b-trypsin [19].…”

Section: Resultsmentioning

confidence: 92%

Conformational studies of [Nphe5]SFTI-1 by means of 2D NMR spectroscopy in conjunction with molecular dynamics calculations

Brzozowski

Stawikowski

Ślusarz

et al. 2015

Journal of Molecular Structure

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“…Interestingly, Analogue 6 displayed chymotryptic inhibition against KLK7 with a potency near to that of its inhibition on the other tryptic enzymes. This is a major improvement as the binding affinity of native SFTI towards chymotrypsin is of around four orders of magnitude weaker than trypsin [35]. …”

Section: Resultsmentioning

confidence: 99%

Tissue Kallikrein Inhibitors Based on the Sunflower Trypsin Inhibitor Scaffold – A Potential Therapeutic Intervention for Skin Diseases

Chen¹,

Kinsler²,

Macmillan

et al. 2016

PLoS ONE

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Tissue kallikreins (KLKs), in particular KLK5, 7 and 14 are the major serine proteases in the skin responsible for skin shedding and activation of inflammatory cell signaling. In the normal skin, their activities are controlled by an endogenous protein protease inhibitor encoded by the SPINK5 gene. Loss-of-function mutations in SPINK5 leads to enhanced skin kallikrein activities and cause the skin disease Netherton Syndrome (NS). We have been developing inhibitors based on the Sunflower Trypsin Inhibitor 1 (SFTI-1) scaffold, a 14 amino acids head-to-tail bicyclic peptide with a disulfide bond. To optimize a previously reported SFTI-1 analogue (I10H), we made five analogues with additional substitutions, two of which showed improved inhibition. We then combined those substitutions and discovered a variant (Analogue 6) that displayed dual inhibition of KLK5 (tryptic) and KLK7 (chymotryptic). Analogue 6 attained a tenfold increase in KLK5 inhibition potency with an Isothermal Titration Calorimetry (ITC) Kd of 20nM. Furthermore, it selectively inhibits KLK5 and KLK14 over seven other serine proteases. Its biological function was ascertained by full suppression of KLK5-induced Protease-Activated Receptor 2 (PAR-2) dependent intracellular calcium mobilization and postponement of Interleukin-8 (IL-8) secretion in cell model. Moreover, Analogue 6 permeates through the cornified layer of in vitro organotypic skin equivalent culture and inhibits protease activities therein, providing a potential drug lead for the treatment of NS.

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Inhibition of bovine α-chymotrypsin by cyclic trypsin inhibitor SFTI-1 isolated from sunflower seeds and its two acyclic analogues

Cited by 8 publications

References 18 publications

Sunflower trypsin inhibitor‐1, proteolytic studies on a trypsin inhibitor peptide and its analogs

Sunflower trypsin inhibitor‐1, proteolytic studies on a trypsin inhibitor peptide and its analogs

Conformational studies of [Nphe5]SFTI-1 by means of 2D NMR spectroscopy in conjunction with molecular dynamics calculations

Tissue Kallikrein Inhibitors Based on the Sunflower Trypsin Inhibitor Scaffold – A Potential Therapeutic Intervention for Skin Diseases

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