Reversible Inhibitors of Serine Proteinases

Wenzel, Herbert R.; Tschesche, Harald

doi:10.1016/b978-012310920-0/50009-7

Cited by 11 publications

(8 citation statements)

References 210 publications

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“…Although in our system we find that P 1 Ala gives a lower K i for HLE than does P 1 Val, this is not the case for all systems that have been studied. As Val is generally considered to be the preferred residue at the P 1 locus, it is common for researchers to replace this residue with Val when re‐directing the specificity of natural inhibitors [58,59]. The Kazal inhibitor BPTI has often been studied because of its small size (58 residues) and potent inhibitory properties.…”

Section: Resultsmentioning

confidence: 99%

“…Similar conclusions have been drawn by other workers. In an attempt to improve further antielastase activity, additional alteration of K15V BPTI at the P 1 ′ and P 2 ′ positions (A16S, R17I) to match those of the α 1 ‐proteinase inhibitor was found to result in a 40‐fold decrease in K d [59]. The importance of the P 4 –S 4 interaction in PPE has been described by Thompson & Blout [60].…”

Section: Resultsmentioning

confidence: 99%

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Selection of human elastase inhibitors from a conformationally constrained combinatorial peptide library

McBride

Freeman

Leatherbarrow

1999

European Journal of Biochemistry

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A resin-bound cyclic peptide library was constructed based on the sequence of the reactive-site loop of Bowman±Birk inhibitor, a proteinase inhibitor protein. The constrained loop sequence, which incorporates the minimal proteinase-binding motif, was retained throughout the library, but selected residues known to be important for inhibitor specificity were randomised. The approach was used to create a`one bead, one peptide' library with 8000 variants resulting from randomization at three target locations in the sequence (P 4 , P 1 and P 2 H ). This library allows us to examine the degree to which variations in this proteinase-binding motif can redirect activity, as well as providing information about the binding specificity of a proteinase target. Screening this library for binding to human leucocyte elastase identified sequences with a strong consensus, and on resynthesis all were found to act as inhibitors, with K i values as low as 65 nm. Human leucocyte elastase is known to have a substrate preference for small alkyl chains at the P 1 locus, with valine being preferred. However, alanine and not the expected valine was found in 21 out of 23 identified sequences. The remaining two sequences had threonine at P 1 , a finding that would be hard to predict based on substrate specificity alone. Further analysis of resynthesized peptides demonstrated that valine substitution results in an analogue that is hydrolysed far more rapidly than ones having library-selected P 1 residues. Testing of the human leucocyte elastase-selected sequences as inhibitors of porcine pancreatic elastase demonstrates a significant difference in the specificity of the P 4 locus between these two proteinases.Keywords: Bowman±Birk inhibitor; canonical loop; combinatorial chemistry; elastase; peptide library.Elastases, which are serine proteinases capable of cleaving the connective tissue elastin, are considered to play important roles in the tissue destruction associated with pulmonary emphysema, rheumatoid arthritis, cystic fibrosis, adult respiratory distress syndrome, chronic bronchitis, and pancreatitis [1,2]. For some of these pathological conditions an imbalance between the amount of elastase and endogenous proteinaceous inhibitor(s) has been implicated. As a result, there has been considerable interest in the design of inhibitors that may restore this balance and/or clarify the role of these enzymes in the above diseases. In addition to natural or engineered inhibitor proteins, which have high molecular masses, researchers have also pursued both peptide-based and nonpeptide small inhibitor compounds [2].In many natural inhibitor proteins, the portion of the inhibitor protein that interacts with the serine proteinase is an extended or`canonical' loop. This is thought to have a structure similar to that of a productively bound substrate [3,4]. Inhibitors behave as limited proteolysis substrates; residues interacting with proteinase at the reactive site of the inhibitor determine specificity and typically reflect the substrate specificit...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Selection of human elastase inhibitors from a conformationally constrained combinatorial peptide library

McBride

Freeman

Leatherbarrow

1999

European Journal of Biochemistry

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“…5,6 One aim of inhibitor research has been to define the minimal requirements for inhibitory activity, in terms both of structural and recognition elements. 6,7 In this regard, the BowmanBirk family of inhibitors has proved particularly useful; this article reviews those peptides based on the Bowman-Birk inhibitory loop that have thus far been described in the literature.…”

Section: Background the Canonical Loop Motifmentioning

confidence: 99%

Peptide mimics of the Bowman–Birk inhibitor reactive site loop

et al. 2002

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Bowman-Birk Inhibitors (BBIs) are small highly cross-linked proteins that typically display an almost symmetrical "double-headed" structure. Each "head" contains an independent proteinase binding domain. The realization that one BBI molecule could form a 1:1:1 complex with two enzymes led early workers to dissect this activity. Now, after three decades of research, it has been possible to isolate the antiproteinase activity as small ( approximately 11 residues), cyclic, synthetic peptides, which display most of the functional aspects of the protein. More recently, it has been found that these peptide fragments are not just a synthetic curiosity-a natural 14-residue cyclic peptide (SFTI-1), which too encapsulates the BBI inhibitory motif, is found to occur in sunflowers. This article reviews the properties of BBI-based peptides (including SFTI-1) and discusses the features that are important for inhibitory activity.

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“…Such an approach has the advantage of allowing incorporation of non-proteinogenic amino acids, but is complicated by the complexity of natural inhibitor proteins. Indeed, one goal of inhibitor research has been the reduction in size and simpli®cation of these proteins to their minimal structural elements (Wenzel & Tschesche, 1995). Our library employed an 11 amino acid residue cyclic peptide template (McBride et al, 1996) derived from the anti-tryptic loop domain of the Bowman Birk inhibitor MAI-D4 (Maeder et al, 1992).…”

Section: Introductionmentioning

confidence: 99%