Inorganic Pyrophosphatase–Nanodiamond Conjugates Hydrolyze Pyrophosphate in Human Synovial Fluid

Abstract

The present work is focused on testing enzyme-based agents for the partial dissolution of calcium pyrophosphate (CaPP i ) deposits in the cartilages and synovial fluid of patients with pyrophosphate arthropathy (CPPD disease). Previously, we suggested that inorganic pyrophosphatases (PPases) immobilized on nanodiamonds of detonation synthesis (NDs) could be appropriate for this purpose. We synthesized and characterized conjugates of NDs and PPases from Escherichia coli and Mycobacterium tuberculosis. The conjugates showed high enzymatic activity and resistance to inhibition by calcium and fluoride. Here, we tested the effectiveness of pyrophosphate (PP i ) hydrolysis by the conjugates in an in vitro model system simulating the ionic composition of the synovial fluid and in the samples of synovial fluid of patients with CPPD via NMR spectroscopy. The conjugates of both PPases efficiently hydrolyzed triclinic crystalline calcium pyrophosphate (t-CPPD) in the model system. We evaluated the number of phosphorus-containing compounds in the synovial fluid, showed the possibility of PP i detection in it, and estimated the hydrolytic activity of the PPase conjugates. The soluble and immobilized PPases were able to hydrolyze a significant amount of PP i (1 mM) in the synovial fluid in short periods of time (24 h). The maximum activity was demonstrated for Mt-PPase immobilized on ND−NH−(CH 2 ) 6 −NH 2 (2.24 U mg −1 ).

Thermophilic Inorganic Pyrophosphatase Ton1914 from Thermococcus onnurineus NA1 Removes the Inhibitory Effect of Pyrophosphate

“…Inorganic pyrophosphorylases are the main enzymes for removing PP i inhibition and play an important role both for health and industrial production. For example, the drug delivery system formed by PPase-nanodiamond is expected to treat calcium pyrophosphate crystal deposition diseases and related pathologic diseases [ 32 , 33 , 34 ]. Fluorescent biosensors made by monitoring the activity of PPases can be utilized to screen for potential inhibitors of PPases, which are associated with many clinical diseases (lung cancer and colorectal cancer, etc.)…”

Versatile Electrochemical Platform Developed By Pyrophosphatase-Guided Triggered-Release System Based on Cu(II) Coordination

“…1 Commonly, inorganic pyrophosphatase (PPase) serves as a ubiquitous hydrolytic enzyme in all domains of life, which can convert pyrophosphate (PPi) into metabolic orthophosphates (Pi) by the form of heat. 2 It is reported that PPase maintains a certain relationship with some biological reactions [3][4][5] (e.g., phosphorus metabolism, carbohydrate metabolism, DNA synthesis, calcium absorption and bone formation) and certain clinical diseases [6][7][8] (e.g., hyperthyroidism, lung adenocarcinomas and colorectal cancer). With the strong rise in demand for the field of clinical medicine, quantitative detection of PPase in biological clinical samples has grown in importance and significance.…”