scholarly journals Detection of the ATPase Activity of the Molecular Chaperones Hsp90 and Hsp72 Using the Transcreener™ ADP Assay Kit

2010 ◽  
Vol 15 (3) ◽  
pp. 279-286 ◽  
Author(s):  
Martin Rowlands ◽  
Craig McAndrew ◽  
Chris Prodromou ◽  
Laurence Pearl ◽  
Andrew Kalusa ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Atpase Activity ◽  
Small Molecule ◽  
Drug Target ◽  
Small Molecule Inhibitors ◽  
Heat Shock Protein 90 ◽  
Cancer Drug ◽  
Cell Growth Inhibition ◽  
Client Proteins

The molecular chaperone heat shock protein 90 (Hsp90) is required for the correct folding and stability of a number of client proteins that are important for the growth and maintenance of cancer cells. Heat shock protein 72 (Hsp72), a co-chaperone of Hsp90, is also emerging as an attractive cancer drug target. Both proteins bind and hydrolyze adenosine triphosphate (ATP), and ATPase activity is essential for their function. Inhibition of Hsp90 ATPase activity leads to the degradation of client proteins, resulting in cell growth inhibition and apoptosis. Several small-molecule inhibitors of the ATPase activity of Hsp90 have been described and are currently being evaluated clinically for the treatment of cancer. A number of methods for the measurement of ATPase activity have been previously used, but not all of these are ideally suited to screening cascades in drug discovery projects. The authors have evaluated the use of commercial reagents (Transcreener™ ADP) for the measurement of ATPase activity of both yeast and human Hsp90 (ATP Km ~500 µM) and human Hsp72 (ATP Km ~1 µM). The low ATPase activity of human Hsp90 and its stimulation by the co-chaperone Aha1 was measured with ease using reduced incubation times, generating robust data (Z′ = 0.75). The potency of several small-molecule inhibitors of both Hsp90 and Hsp72 was determined using the Transcreener™ reagents and compared well to that determined using other assay formats.

scholarly journals Small Molecule Inhibitors Targeting the Heat Shock Protein System of Human Obligate Protozoan Parasites

2019 ◽  
Vol 20 (23) ◽  
pp. 5930 ◽  
Author(s):  
Zininga ◽  
Shonhai
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Small Molecule ◽  
Molecular Chaperones ◽  
Small Molecule Inhibitors ◽  
Protozoan Parasites ◽  
Obligate Intracellular ◽  
Human Host ◽  
Shock Proteins

Obligate protozoan parasites of the kinetoplastids and apicomplexa infect human cells to complete their life cycles. Some of the members of these groups of parasites develop in at least two systems, the human host and the insect vector. Survival under the varied physiological conditions associated with the human host and in the arthropod vectors requires the parasites to modulate their metabolic complement in order to meet the prevailing conditions. One of the key features of these parasites essential for their survival and host infectivity is timely expression of various proteins. Even more importantly is the need to keep their proteome functional by maintaining its functional capabilities in the wake of physiological changes and host immune responses. For this reason, molecular chaperones (also called heat shock proteins)—whose role is to facilitate proteostasis—play an important role in the survival of these parasites. Heat shock protein 90 (Hsp90) and Hsp70 are prominent molecular chaperones that are generally induced in response to physiological stress. Both Hsp90 and Hsp70 members are functionally regulated by nucleotides. In addition, Hsp70 and Hsp90 cooperate to facilitate folding of some key proteins implicated in cellular development. In addition, Hsp90 and Hsp70 individually interact with other accessory proteins (co-chaperones) that regulate their functions. The dependency of these proteins on nucleotide for their chaperone function presents an Achille’s heel, as inhibitors that mimic ATP are amongst potential therapeutic agents targeting their function in obligate intracellular human parasites. Most of the promising small molecule inhibitors of parasitic heat shock proteins are either antibiotics or anticancer agents, whose repurposing against parasitic infections holds prospects. Both cancer cells and obligate human parasites depend upon a robust protein quality control system to ensure their survival, and hence, both employ a competent heat shock machinery to this end. Furthermore, some inhibitors that target chaperone and co-chaperone networks also offer promising prospects as antiparasitic agents. The current review highlights the progress made so far in design and application of small molecule inhibitors against obligate intracellular human parasites of the kinetoplastida and apicomplexan kingdoms.

Application of Target-Mediated Drug Disposition Model to Small Molecule Heat Shock Protein 90 Inhibitors

2013 ◽  
Vol 41 (6) ◽  
pp. 1285-1294 ◽  
Author(s):  
Shinji Yamazaki ◽  
Zhongzhou Shen ◽  
Ying Jiang ◽  
Bill J. Smith ◽  
Paolo Vicini
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Small Molecule ◽  
Drug Disposition ◽  
Heat Shock Protein 90 ◽  
Target Mediated Drug Disposition ◽  
Disposition Model

scholarly journals A Brain Penetrating Heat-Shock Protein 90 Inhibitor NXD30001 Inhibits Glioblastoma as a Monotherapy or in Combination With Radiation

Neurosurgery ◽  
2019 ◽  
Vol 66 (Supplement_1) ◽  
Author(s):  
Hao Chen ◽  
Jialiang Wang ◽  
Hengli Tian
Keyword(s):  
Stem Cells ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Median Survival ◽  
Therapeutic Potential ◽  
Heat Shock Protein 90 ◽  
Tumor Bearing ◽  
Client Proteins

Abstract INTRODUCTION It has been increasingly recognized that glioblastoma multiforme (GBM) is a highly heterogeneous disease, which is initiated and sustained by molecular alterations in an array of signal transduction pathways. Heat-shock protein 90 (Hsp90) is a molecular chaperone to be critically implicated in folding and activation of a diverse group of client proteins, many of which are key regulators of important glioblastoma biology. METHODS To determine the therapeutic potential of targeting Hsp90 in glioblastoma, we assessed the anti-neoplastic efficacy of NXD30001, a brain-penetrating Hsp90 inhibitor as a monotherapy or in combination with radiation, both in Vitro and in Vivo. RESULTS Our results demonstrated that NXD30001 potently inhibited neurosphere formation, growth and survival of CD133 + glioblastoma stem cells (GSCs) with the half maximal inhibitory concentrations (IC50) at low nanomolar concentrations. At suboptimal concentrations, inhibition of Hsp90 did not exert cytotoxic activity but rather increased radiosensitivity in GSCs. CD133- GBM cells were less sensitive and not radiosensitized by NXD30001. In lines with its cytotoxic and radiosensitizing effects, NXD30001 dose-dependently decreased phosphorylation protein levels of multiple Hsp90 client proteins, including those playing key roles in GSCs, such as EGFR, Akt, c-Myc, and Notch1. In addition, combining NXD30001 with radiation could impair DNA damage response and ER stress response to induce apoptosis of GSCs. Treatment of orthotopic glioblastoma tumors with NXD30001 extended median survival of tumor-bearing mice by approximately 20% (treated 37 days vs vehicle 31 d, P = .0026). Radiation alone increased median survival of tumor-bearing mice from 31 to 38 d, combination with NXD30001 further extended survival to 43 d (P = .0089). CONCLUSION Our results suggest that GBM stem cells (CD133+) are more sensitive to NXD30001 than non-stem GBM cells (CD133-). Furthermore, combination NXD30001 with radiation significantly inhibits GBM progression than use it as a monotherapy by targeting GSCs.

scholarly journals Heat Shock Protein 90 as a Drug Target against Protozoan Infections

2010 ◽  
Vol 285 (49) ◽  
pp. 37964-37975 ◽  
Author(s):  
Rani Pallavi ◽  
Nainita Roy ◽  
Rishi Kumar Nageshan ◽  
Pinaki Talukdar ◽  
Soundara Raghavan Pavithra ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Drug Target ◽  
Heat Shock Protein 90 ◽  
Protozoan Infections

6-alkylsalicylic acid analogues inhibit in vitro ATPase activity of heat shock protein 90

2010 ◽  
Vol 33 (12) ◽  
pp. 1997-2001 ◽  
Author(s):  
Cheng-Zhu Wu ◽  
An Na Moon ◽  
Oksik Choi ◽  
Sun-Young Kang ◽  
Jung Joon Lee ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Atpase Activity ◽  
Heat Shock Protein 90 ◽  
Alkylsalicylic Acid

Heat shock protein 90 as a potential drug target against surra

Parasitology ◽  
2014 ◽  
Vol 141 (9) ◽  
pp. 1148-1155 ◽  
Author(s):  
ANKIT K. ROCHANI ◽  
CHANDAN MITHRA ◽  
MEETALI SINGH ◽  
UTPAL TATU
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Drug Target ◽  
Animal Health ◽  
Heat Shock Protein 90 ◽  
Potential Drug Target ◽  
Potential Drug ◽  
Priority List ◽  
Animal Populations ◽  
Animal Trypanosomiasis

SUMMARYTrypanosomiasis is caused by Trypanosoma species which affect both human and animal populations and pose a major threat to developing countries. The incidence of animal trypanosomiasis is on the rise. Surra is a type of animal trypanosomiasis, caused by Trypanosoma evansi, and has been included in priority list B of significant diseases by the World Organization of Animal Health (OIE). Control of surra has been a challenge due to the lack of effective drugs and vaccines and emergence of resistance towards existing drugs. Our laboratory has previously implicated Heat shock protein 90 (Hsp90) from protozoan parasites as a potential drug target and successfully demonstrated efficacy of an Hsp90 inhibitor in cell culture as well as a pre-clinical mouse model of trypanosomiasis. This article explores the role of Hsp90 in the Trypanosoma life cycle and its potential as a drug target. It appears plausible that the repertoire of Hsp90 inhibitors available in academia and industry may have value for treatment of surra and other animal trypanosomiasis.

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