Lumbrokinase for degradation and reduction of amyloid fibrils associated with amyloidosis

Proteases, a powerful biochemical tool in the service of medicine, clinical and pharmaceutical

Proteases, enzymes that hydrolyze peptide bonds, have various applications in medicine, clinical applications, and pharmaceutical development. They are used in cancer treatment, wound debridement, contact lens cleaning, prion degradation, biofilm removal, and fibrinolytic agents. Proteases are also crucial in cardiovascular disease treatment, emphasizing the need for safe, affordable, and effective fibrinolytic drugs. Proteolytic enzymes and protease biosensors are increasingly used in diagnostic and therapeutic applications. Advanced technologies, such as nanomaterials-based sensors, are being developed to enhance the sensitivity, specificity, and versatility of protease biosensors. These biosensors are becoming effective tools for disease detection due to their precision and rapidity. They can detect extracellular and intracellular proteases, as well as fluorescence-based methods for real-time and label-free detection of virus-related proteases. The active utilization of proteolytic enzymatic biosensors is expected to expand significantly in biomedical research, in-vitro model systems, and drug development. We focused on journal articles and books published in English between 1982 and 2024 for this study.

The potential of lumbrokinase and serratiopeptidase for the degradation of Aβ 1-42 peptide - an in vitro and in silico approach

BACKGROUND

Alzheimer's disease (AD) is diagnosed with the deposition of insoluble β-amyloid (Aβ) peptides in the neuropil of the brain leading to dementia. The extracellular deposition of the fibrillar Aβ peptide on the neurons is known as senile plaques. Therefore, Aβ degradation and clearance from the human body is a promising therapeutic approach in the medication of AD.

METHODS

In the current study, the enzyme lumbrokinase (LK) was extracted and purified from earthworm and its activity was utilized toward Aβ 1-42 amyloids degradation in vitro alongside with an additional enzyme serratiopeptidase (SP) considering nattokinase (NK) as a standard.

RESULTS

The output of this study revealed that preformed Aβ 1-42 amyloids was disintegrated by both LK and SP, as demonstrated from fluorescence assay using Thioflavin T dye. In addition, dynamic light scattering study revealed the lower size of the preformed fibrils Aβ 1-42 at various time intervals after incubation with the enzymes LK and SP. Furthermore, in silico approach showed high affinity thermodynamically favorable interaction of LK as well as SP toward Aβ 1-42 amyloid. Finally, the toxicity of degraded preformed Aβ 1-42 amyloid was assessed by MTT assay which showed reduced toxicity of enzyme treated Aβ 1-42 amyloid compared to only Aβ 1-42 amyloid.

CONCLUSION

The findings of the present study indicated that LK and SP, not only had Aβ 1-42 amyloid degrading potential, but also could reduce the toxicity which can make them a suitable drug candidate for AD. Furthermore, the in vivo studies are needed to be executed in future.

Are fibrinaloid microclots a cause of autoimmunity in Long Covid and other post-infection diseases?

It is now well established that the blood-clotting protein fibrinogen can polymerise into an anomalous form of fibrin that is amyloid in character; the resultant clots and microclots entrap many other molecules, stain with fluorogenic amyloid stains, are rather resistant to fibrinolysis, can block up microcapillaries, are implicated in a variety of diseases including Long COVID, and have been referred to as fibrinaloids. A necessary corollary of this anomalous polymerisation is the generation of novel epitopes in proteins that would normally be seen as 'self', and otherwise immunologically silent. The precise conformation of the resulting fibrinaloid clots (that, as with prions and classical amyloid proteins, can adopt multiple, stable conformations) must depend on the existing small molecules and metal ions that the fibrinogen may (and is some cases is known to) have bound before polymerisation. Any such novel epitopes, however, are likely to lead to the generation of autoantibodies. A convergent phenomenology, including distinct conformations and seeding of the anomalous form for initiation and propagation, is emerging to link knowledge in prions, prionoids, amyloids and now fibrinaloids. We here summarise the evidence for the above reasoning, which has substantial implications for our understanding of the genesis of autoimmunity (and the possible prevention thereof) based on the primary process of fibrinaloid formation.

Attenuation of subcutaneous insulin induced amyloid mass in vivo using Lumbrokinase and Serratiopeptidase

The protein misfolded structure called amyloids is related with extensive range of pathologies like local amyloidosis and neurodegenerative diseases. Several studies have reported the potential of insulin to generate local amyloidosis under certain state. Reports also showed that fibrils of insulin generated local amyloid mass due to continuous subcutaneous injection in mouse as well as rat. The present study was designed to examine the consequence of insulin fibril injections in rats, as well as the ability of enzymes, Lumbrokinase (LK) and Serratiopeptidase (SP) in diminishing this amyloid mass progression. The results showed that insulin fibrils generated amyloid masses in rats after subcutaneous injection for two weeks which was significantly condensed in size for the groups injected with insulin fibrils combined with LK or SP. At higher doses of LK and SP, the absence of amyloid structure was observed in histopathological studies. Light microscopy, polarized microscopy as well as Lumia live in vivo imaging system was used to analyze the results. In conclusion, the overall outcome of this study showed the anti-amyloid potential of enzyme LK and SP in the attenuation of local amyloidosis.

The Potential of Serratiopetidase and Lumbrokinase for the Degradation of Prion Peptide 106-126 - an In Vitro and In Silico Perspective

BACKGROUND

PrPC is a host-encoded prion protein, which gets post translationally modified into a transmissible, β-sheet rich disease associated protein called PrPSc, responsible for the Prion disease including mad cow disease in cattle and CJD in humans. The PrP 106-126 region in PrPSc peptide initiates the conformational change in that protein leading to fibrillation. Any agent that can destabilize or disintegrate such proteins can be served as a potential drug candidate for Prion diseases.

METHODS

In the present study, an enzyme Lumbrokinase (LK) was isolated from earthworm and its activity was exploited towards PrP 106-126 amyloids in vitro along with another enzyme Serratiopeptidase (SP) taking Nattokinase (NK) as a standard.

RESULTS

The results showed that PrP 106-126 amyloid formation was inhibited by both LK and SP, as evidenced from Thioflavin T fluorescence assay. Further, the size of fibrils as estimated by dynamic light scattering, was also found to be lower at different time intervals after incubation of the prion amyloids with LK and SP. Additionally, the molecular dynamics simulation revealed the thermodynamically favorable interaction of PrP 106-126 with LK as well as with SP with high affinity.

CONCLUSION

Finally, the toxicity of the disintegrated amyloids was assessed using PC12 cell lines which showed higher cell viability in case of LK and SP treated amyloids compared to only PrP 106- 126 amyloid treatment. Altogether, the study concluded that the serine proteases like LK and SP have the potential to disintegrate PrP 106-126 amyloids with improved cell viability. The in vivo studies are needed to be executed in future.

Label Free Ultrasmall Fluoromagnetic Ferrite-clusters for Targeted Cancer Imaging and Drug Delivery

OBJECTIVE

The label free ultrasmall fluorescent ferrite clusters have been engineered in a controlled fashion which was stabilized by serum protein and functionalized by folic acid for the application of targeted multimodal optical and Magnetic Resonance (MR) cancer imaging.

METHODS

The ultra-small manganese ferrite nanoclusters (PMNCs) with a diameter of 4 nm have a commendable effect on the longitudinal (T1) and transverse (T2) relaxation in MR imaging that was evident from the phantom and animal MRI.

RESULTS

The calculated longitudinal molar relaxivity of nanoclusters was found to be 6.9 ± 0.10 mM-1 S-1 which was exactly 2.22 times better than the conventional Gd-DOTA and their 4.01 ratio of the transverse (r2) and longitudinal (r1) relaxivities made them a potential candidate for both T1 and T2 contrast agents in MRI. In addition, the fluorescence-based small animal imaging showed folic acid driven accumulated fluorescent signal at the tumour site to conclude the capacity of PMNCs for targeted fluorescence imaging of cancer diagnosis.

CONCLUSION

The cytotoxicity assay and histopathology studies were the evidence for their safe biodistribution in animal systems. Furthermore, the protein encapsulated clusters have the ability to deliver the anticancer drug Methotrexate (MTX) to the cancer tissues with a sustained manner. Therefore, one can conclude the remarkable efficacy of architect nanoclusters for theragnosis.

Camouflaged Nanosilver with Excitation Wavelength Dependent High Quantum Yield for Targeted Theranostic

The present study shows the thorough investigations on optical properties and hydrodynamic diameters of glutathione (GSH) stabilized nanosilver clusters (AgNC) at different stages of synthesis and engineering for the optimized absolute quantum yield to generate fluorescent images of Dalton Lymphoma Ascites (DLA) tumour bearing mice. The initial increment of quantum yield was wavelength dependent and finally it became 0.509 which was due to the camouflaging or entrapment of AgNC in macrophages membranes. The potentiality of macrophages membrane camouflaged silver nanoclusters (AgM) was reflected in the cell viability assay and confocal based live dead cell assay where the AgM has better cell killing effect compared to AgNC with reduced dosage and in vivo mice imaging generated the clear visualization at the tumour sites. Therefore, from the present study, it can be considered that the camouflaged nanosilver can be used for targeted theranostic applications.

Pathophysiological significance of protein hydrophobic interactions: An emerging hypothesis

Fibrinogen is a unique protein that is converted into an insoluble fibrin in a single enzymatic event, which is a characteristic feature of fibrinogen due to its susceptibility to fibrinolytic degradation and dissolution. Although thrombosis is a result of activated blood coagulation, no explanation is being offered for the persistent presence of fibrin deposits in the affected organs. A classic example is stroke, in which the thrombolytic therapy is effective only during the first 3-4 h after the onset of thrombosis. This phenomenon can now be explained in terms of the modification of fibrinogen structure induced by hydroxyl radicals generated during the period of ischemia caused, in turn, by the blocking of the blood flow within the obstructed vessels. Fibrinogen modification involves intra-to intermolecular disulfide rearrangement induced by the reductive power of hydroxyl radicals that result in the exposition of buried hydrophobic epitopes. Such epitopes react readily with each other forming linkages stronger than the peptide covalent bonds, thus rendering them resistant to the proteolytic degradation. Also, limited reduction of human serum albumin (HSA) generates hydrophobic polymers that form huge insoluble complexes with fibrinogen. Consequently, such insoluble copolymers can be deposited within the circulation of various organs leading to their dysfunction. In conclusion, the study of protein hydrophobic interactions induced by a variety of nutritional and/or environmental factors can provide a rational explanation for a number of pathologic conditions including cardiovascular, neurologic, and other degenerative diseases including cancer.

Effect of Mesoporous Nano Water Reservoir on MR Relaxivity

In the present work, an attempt was made to engineer a mesoporous silica coated magnetic nanoparticles (MNF@mSiO₂) for twin mode contrast in magnetic resonance imaging (MRI) with reduced toxicity. Superparamagnetic manganese ferrite nanoparticles were synthesized with variable mesoporous silica shell thickness to control the water molecules interacting with metal oxide core. 178 nm was the optimum hydrodynamic diameter of mesoporous ferrite core-shell nanoparticles that showed maximum longitudinal relaxation time (T1) and transverse relaxation time (T2) in MRI due to the storage of water molecules in mesoporous silica coating. Besides the major role of mesoporous silica in controlling relaxivity, mesoporous silica shell also reduces the toxicity and enhances the bioavailability of superparamagnetic manganese ferrite nanoparticles. The in vitro toxicity assessment using HepG2 liver carcinoma cells shows that the mesoporous silica coating over ferrite nanoparticles could exert less toxicity compared to the uncoated particle.