scholarly journals Purification of native p94, a muscle-specific calpain, and characterization of its autolysis

1998 ◽  
Vol 335 (3) ◽  
pp. 589-596 ◽  
Author(s):  
Kayoko KINBARA ◽  
Shoichi ISHIURA ◽  
Shigeo TOMIOKA ◽  
Hiroyuki SORIMACHI ◽  
Seon-Yong JEONG ◽  
...  

p94, a skeletal muscle-specific calpain, has attracted much attention because its gene is responsible for limb-girdle muscular dystrophy type 2A. p94, however, has not been characterized at the protein and enzyme levels, owing to its very rapid autolysis. In the present study, a purification procedure for p94 was first established by using a recombinant inactive p94 expressed in COS cells in which the active site cysteine residue was changed to serine [p94(C129S)]. The isolation of native p94 from rabbit skeletal muscle by the established method with conventional procedures was extremely difficult because p94 became highly unstable in a crude extract on the addition of NaCl for separation. Purification of native p94 was possible with an antibody-affinity column but only as an inactive enzyme; p94(C129S) was purified as a homodimer. Characterization of p94, especially autolysis, was performed with partly purified native p94 and p94(C129S). The autolysis of p94, which consisted at least partly of an intermolecular reaction, proceeded in three consecutive steps; 60 and 58 kDa fragments were produced as intermediates before a stable 55 kDa fragment appeared. Autolysis of p94 was regarded as a degradative step rather than for the activation of the enzyme. All the autolysis cleavage sites were located in the p94-specific insertion sequence 1 region, which explains why p94 is unstable compared with the other calpains. The autolysis sites in p94 clearly showed a different specificity relative to the autolytic and proteolytic cleavage sites of the ubiquitous µ- and m-calpains, in its preference for residues at the P3 to P1´ sites, indicating a distinct substrate specificity and function for the muscle enzyme.

1997 ◽  
Vol 322 (3) ◽  
pp. 771-776 ◽  
Author(s):  
Andreas HUMM ◽  
Erich FRITSCHE ◽  
Karlheinz MANN ◽  
Martin GÖHL ◽  
Robert HUBER

Creatine and its phosphorylated form play a central role in the energy metabolism of muscle and nerve tissues. l-Arginine: glycine amidinotransferase (AT) catalyses the committed step in the formation of creatine. The mitochondrial and cytosolic forms of the enzyme are believed to derive from the same gene by alternative splicing. We have expressed recombinant human AT in Escherichia coliwith two different N-termini, resembling the longest two forms of the enzyme that we had isolated recently from porcine kidney mitochondria as a mixture. The enzymes were expressed with N-terminal histidine tags followed by factor Xa-cleavage sites. We established a new method for the removal of N-terminal fusion peptides by means of an immobilized snake venom prothrombin activator. We identified cysteine-407 as the active-site residue of AT by radioactive labelling and isolation of labelled peptides, and by site-directed mutagenesis of the protein.


2018 ◽  
Author(s):  
Jérémie Piton ◽  
Anthony Vocat ◽  
Andréanne Lupien ◽  
Caroline Foo ◽  
Olga Riabova ◽  
...  

ABSTRACTMacozinone (MCZ) is a tuberculosis (TB) drug candidate that specifically targets the essential flavoenzyme DprE1 thereby blocking synthesis of the cell wall precursor decaprenyl phosphoarabinose (DPA) and provoking lysis of Mycobacterium tuberculosis. As part of the MCZ back-up program we exploited structure-guided drug design to produce a new series of sulfone-containing derivatives, 2-sulphonylpiperazin 8-nitro 6-trifluoromethyl 1,3-benzothiazin-4-one, or sPBTZ. These compounds are less active than MCZ but have a better solubility profile and some derivatives display enhanced stability in microsomal assays. DprE1 was efficiently inhibited by sPBTZ and covalent adducts with the active site cysteine residue (C387) were formed. However, despite the H-bonding potential of the sulfone group no additional bonds were seen in the crystal structure of the sPBTZ-DprE1 complex with compound 11326127 as compared to MCZ. Compound 11626091, the most advanced sPBTZ, displayed good antitubercular activity in the murine model of chronic TB but was less effective than MCZ. Nonetheless, further testing of this MCZ backup compound is warranted as part of combination treatment with other TB drugs.


2021 ◽  
Vol 22 (5) ◽  
pp. 2501
Author(s):  
Sonja Hinz ◽  
Dominik Jung ◽  
Dorota Hauert ◽  
Hagen S. Bachmann

Geranylgeranyltransferase type-I (GGTase-I) represents an important drug target since it contributes to the function of many proteins that are involved in tumor development and metastasis. This led to the development of GGTase-I inhibitors as anti-cancer drugs blocking the protein function and membrane association of e.g., Rap subfamilies that are involved in cell differentiation and cell growth. In the present study, we developed a new NanoBiT assay to monitor the interaction of human GGTase-I and its substrate Rap1B. Different Rap1B prenylation-deficient mutants (C181G, C181S, and ΔCQLL) were designed and investigated for their interaction with GGTase-I. While the Rap1B mutants C181G and C181S still exhibited interaction with human GGTase-I, mutant ΔCQLL, lacking the entire CAAX motif (defined by a cysteine residue, two aliphatic residues, and the C-terminal residue), showed reduced interaction. Moreover, a specific, peptidomimetic and competitive CAAX inhibitor was able to block the interaction of Rap1B with GGTase-I. Furthermore, activation of both Gαs-coupled human adenosine receptors, A2A (A2AAR) and A2B (A2BAR), increased the interaction between GGTase-I and Rap1B, probably representing a way to modulate prenylation and function of Rap1B. Thus, A2AAR and A2BAR antagonists might be promising candidates for therapeutic intervention for different types of cancer that overexpress Rap1B. Finally, the NanoBiT assay provides a tool to investigate the pharmacology of GGTase-I inhibitors.


2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Jérémie Piton ◽  
Anthony Vocat ◽  
Andréanne Lupien ◽  
Caroline S. Foo ◽  
Olga Riabova ◽  
...  

ABSTRACT Macozinone (MCZ) is a tuberculosis (TB) drug candidate that specifically targets the essential flavoenzyme DprE1, thereby blocking synthesis of the cell wall precursor decaprenyl phosphoarabinose (DPA) and provoking lysis of Mycobacterium tuberculosis. As part of the MCZ backup program, we exploited structure-guided drug design to produce a new series of sulfone-containing derivatives, 2-sulfonylpiperazin 8-nitro 6-trifluoromethyl 1,3-benzothiazin-4-one, or sPBTZ. These compounds are less active than MCZ but have a better solubility profile, and some derivatives display enhanced stability in microsomal assays. DprE1 was efficiently inhibited by sPBTZ, and covalent adducts with the active-site cysteine residue (C387) were formed. However, despite the H-bonding potential of the sulfone group, no additional bonds were seen in the crystal structure of the sPBTZ-DprE1 complex with compound 11326127 compared to MCZ. Compound 11626091, the most advanced sPBTZ, displayed good antitubercular activity in the murine model of chronic TB but was less effective than MCZ. Nonetheless, further testing of this MCZ backup compound is warranted as part of combination treatment with other TB drugs.


Biochemistry ◽  
2005 ◽  
Vol 44 (30) ◽  
pp. 10339-10348 ◽  
Author(s):  
Stephen J. Brokx ◽  
Richard A. Rothery ◽  
Guijin Zhang ◽  
Derek P. Ng ◽  
Joel H. Weiner

1968 ◽  
Vol 108 (5) ◽  
pp. 861-866 ◽  
Author(s):  
S. S. Husain ◽  
G. Lowe

Papain that had been irreversibly inhibited with 1,3-dibromo[2−14C]acetone was reduced with sodium borohydride and carboxymethylated with iodoacetic acid. After digestion with trypsin and α-chymotrypsin the radioactive peptides were purified chromatographically. Their amino acid composition indicated that cysteine-25 and histidine-106 were cross-linked. Since cysteine-25 is known to be the active-site cysteine residue, histidine-106 must be the active-site histidine residue.


Biochemistry ◽  
2018 ◽  
Vol 57 (38) ◽  
pp. 5513-5523 ◽  
Author(s):  
Matthias Fellner ◽  
Joel A. Rankin ◽  
Benoît Desguin ◽  
Jian Hu ◽  
Robert P. Hausinger

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