scholarly journals Tailoring tissue inhibitor of metalloproteinases-3 to overcome the weakening effects of the cysteine-rich domains of tumour necrosis factor-alpha converting enzyme

2003 ◽  
Vol 371 (2) ◽  
pp. 369-376 ◽  
Author(s):  
Meng-Huee LEE ◽  
Philippa DODDS ◽  
Vandana VERMA ◽  
Klaus MASKOS ◽  
Vera KNÄUPER ◽  
...  

Tumour necrosis factor-α (TNF-α) converting enzyme (TACE) is a membrane-anchored, multiple-domain zinc metalloproteinase responsible for the release of the potent pro-inflammatory cytokine, TNF-α. The extracellular part of the active enzyme is composed of a catalytic domain and several cysteine-rich domains. Previously, we reported that these cysteine-rich domains significantly weakened the inhibitory potency of the N-terminal-domain form of tissue inhibitor of metalloproteinases-3 (N-TIMP-3). In the present paper, we describe a novel strategy developed to overcome this weakening effect. We have engineered a new generation of N-TIMP-3 mutants that are capable of withstanding the repulsion of the cysteine-rich domains by the formation of electrostatic bonds with the catalytic domain of the enzyme. These N-TIMP-3 mutants displayed markedly improved binding affinity with the soluble extracellular domain form of recombinant TACE. With Ki (app) values of <0.1nM, these mutants were dramatically better than the wild-type N-TIMP-3 [Ki (app) 1.7nM]. We accounted for this by proposing that Glu31, an acidic residue situated at the base of the AB-loop of N-TIMP-3, is drawn into contact with Lys315, a prominent basic residue adjacent to the TACE catalytic site. The mutagenesis strategy involved reorientation of the edge of N-TIMP-3; in particular, the β-strand A where Glu31 was located. Further expression of one of the mutants, Lys26/27/30/76→Glu, in a mammalian expression system confirmed that TIMP-3 associates with the extracellular matrix via its C-terminal domain.

2002 ◽  
Vol 364 (1) ◽  
pp. 227-234 ◽  
Author(s):  
Meng-Huee LEE ◽  
Vandana VERMA ◽  
Klaus MASKOS ◽  
Deepa NATH ◽  
Vera KNÄUPER ◽  
...  

We previously reported that full-length tissue inhibitor of metalloproteinase-3 (TIMP-3) and its N-terminal domain form (N-TIMP-3) displayed equal binding affinity for tissue necrosis factor-α (TNF-α)-converting enzyme (TACE). Based on the computer graphic of TACE docked with a TIMP-3 model, we created a number of N-TIMP-3 mutants that showed significant improvement in TACE inhibition. Our strategy was to select those N-TIMP-3 residues that were believed to be in actual contact with the active-site pockets of TACE and mutate them to amino acids of a better-fitting nature. The activities of these mutants were examined by measuring their binding affinities (Kappi) and association rates (kon) against TACE. Nearly all mutants at position Thr-2 exhibited slightly impaired affinity as well as association rate constants. On the other hand, some Ser-4 mutants displayed a remarkable increase in their binding tightness with TACE. In fact, the binding affinities of several mutants were less than 60pM, beyond the sensitivity limits of fluorimetric assays. Further studies on cell-based processing of pro-TNF-α demonstrated that wild-type N-TIMP-3 and one of its tight-binding mutants, Ser-4Met, were capable of inhibiting the proteolytic shedding of TNF-α. Furthermore, the Ser-4Met mutant was also significantly more active (P<0.05) than the wild-type N-TIMP-3 in its cellular inhibition. Comparison of N-TIMP-3 and full-length TIMP-3 revealed that, despite their identical TACE-interaction kinetics, the latter was nearly 10 times more efficient in the inhibition of TNF-α shedding, with concomitant implications for the importance of the TIMP-3 C-terminal domain in vivo.


2004 ◽  
Vol 271 (13) ◽  
pp. 2808-2820 ◽  
Author(s):  
Monika Bzowska ◽  
Natalia Jura ◽  
Adam Lassak ◽  
Roy A. Black ◽  
Joanna Bereta

2003 ◽  
Vol 70 ◽  
pp. 39-52 ◽  
Author(s):  
Roy A. Black ◽  
John R. Doedens ◽  
Rajeev Mahimkar ◽  
Richard Johnson ◽  
Lin Guo ◽  
...  

Tumour necrosis factor α (TNFα)-converting enzyme (TACE/ADAM-17, where ADAM stands for a disintegrin and metalloproteinase) releases from the cell surface the extracellular domains of TNF and several other proteins. Previous studies have found that, while purified TACE preferentially cleaves peptides representing the processing sites in TNF and transforming growth factor α, the cellular enzyme nonetheless also sheds proteins with divergent cleavage sites very efficiently. More recent work, identifying the cleavage site in the p75 TNF receptor, quantifying the susceptibility of additional peptides to cleavage by TACE and identifying additional protein substrates, underlines the complexity of TACE-substrate interactions. In addition to substrate specificity, the mechanism underlying the increased rate of shedding caused by agents that activate cells remains poorly understood. Recent work in this area, utilizing a peptide substrate as a probe for cellular TACE activity, indicates that the intrinsic activity of the enzyme is somehow increased.


1995 ◽  
Vol 144 (3) ◽  
pp. 457-462 ◽  
Author(s):  
G Haskó ◽  
I J Elenkov ◽  
V Kvetan ◽  
E S Vizi

Abstract The effect of selective block of α2-adrenoreceptors on plasma levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and corticosterone induced by bacterial lipopolysaccharide (LPS) was investigated in mice using ELISA and RIA. It was found that the LPS-induced TNF-α response was significantly blunted in mice pretreated with CH-38083, a novel and highly selective α2-adrenoreceptor antagonist (the α2/α1 ratio is >2000). In contrast, LPS-induced increases in both corticosterone and IL-6 plasma levels were further increased by CH-38083. Since it has recently been shown that the selective block of α2-adrenoreceptors located on noradrenergic axon terminals resulted in an increase in the release of noradrenaline (NA), both in the central and peripheral nervous systems, and, in our experiments, that propranolol prevented the effect of α2-adrenoreceptor blockade on TNF-α plasma levels induced by LPS, it seems likely that the excessive stimulation by NA of β-adrenoreceptors located on cytokine-secreting immune cells is responsible for this action. Since it is generally accepted that increased production of TNF-α is involved in the pathogenesis of inflammation and endotoxin shock on the one hand, and corticosterone and even IL-6 are known to possess anti-inflammatory properties on the other hand, it is suggested that the selective block of α2-adrenoreceptors might be beneficial in the treatment of inflammation and/or endotoxin shock. Journal of Endocrinology (1995) 144, 457–462


2016 ◽  
Vol 2 (5) ◽  
pp. 96-98
Author(s):  
Valentina Canti ◽  
◽  
Elena Baldissera ◽  
Susanna Rosa ◽  
Giuseppe A. Ramirez ◽  
...  

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