Relationship Between Acrylamide Concentration and Enzymatic Activity in An Improved Single Fibrin Zymogram Gel System

Rapid extraction and purification of lumbrokinase from Lumbricus rubellus using a hollow fiber membrane and size exclusion chromatography

OBJECTIVES

To develop a purification process using hollow fiber membrane separation combined with size exclusion chromatography for the extraction of lumbrokinase from earthworms (Lumbricus rubellus).

RESULTS

To extract the protein, the earthworms were first homogenized for 10 min, to produce ultrafine particles. Polyether sulfone hollow fiber membranes with MW cut offs of 50 and 6 kDa were used for initial purification of the crude extract. Further purification was carried out on a Sephadex G-75 column, and yielded three fractions of high purity protein. One of these fractions showed fibrinolytic activity.

CONCLUSIONS

Three samples of high purity protein were obtained and one protein (LK1) showed strong fibrinolytic activity. The method has higher purification efficiency in comparison with existing methods.

Comparative proteomic analysis of the sun- and freeze-dried earthworm Eisenia fetida with differentially thrombolytic activities

The dried earthworm is a traditional thrombolytic medicine in East Asia. Its thrombolytic mechanism has been extensively studied. However, the effects of drying process on thrombolysis were rarely investigated. Herein, we compared the thrombolytic activity of earthworm Eisenia fetida processed by sun-drying to that by freeze-drying. Fibrin plate and blood clot lysis assays showed that freeze-dried earthworms gave dramatically higher fibrinolytic and thrombolytic activities than the sun-dried earthworms. To address the thrombolytic difference, comparative proteomic analysis was carried out using fibrin zymography and two-dimensional gel electrophoresis (2-DE). The freeze- and sun-dried earthworms generated remarkably different 2-DE protein spot patterns. A total of 126 differential protein spots were detected, 83 of them were identified by matrix-assisted laser desorption/ionization-tandem time-of-flight mass spectrometry and database searching with 13 quantitative changes and 70 qualitative changes. Five of these differential proteins were identified as fibrinolytic proteases (lumbrokinases), responsible for dissolving fibrin, the main protein component of thrombus. The total abundance of these fibrinolytic proteases in the freeze-dried earthworms was significantly higher, consistent with the results of fibrin zymography. Therefore, the higher concentration of fibrinolytic enzymes along with their broad substrate specificity explained the stronger fibrinolytic and thrombolytic activities of the freeze-dried earthworms. This study suggests that freeze-drying represents an improved processing method for earthworm as the thrombolytic therapy in the future.

BIOLOGICAL SIGNIFICANCE

Thrombosis has become one of the biggest concerns all over the world. The dried earthworms have been intensively used as thrombolytic agents. Its thrombotic mechanism has been studied by the modern pharmacological researches. However, the drying procedure of the earthworm and its effects on the thrombolysis were rarely investigated. The present study compared the thrombolytic effects of the freeze-dried and the normal dried earthworm E. fetida. To better understand the underlying mechanisms for differential thrombolytic effects, the fibrin zymography and the two-dimensional gel electrophoresis (2-DE) were employed to identify sets of differential proteins. Therefore, this study provides not only the comparative proteomic analysis but also molecular mechanism underlying the differential thrombolytic effects.

Intestinal Absorption of Fibrinolytic and Proteolytic Lumbrokinase Extracted from Earthworm, Eisenia andrei

To investigate the intestinal absorption of a fibrinolytic and proteolytic lumbrokinase extracted from Eisenia andrei, we used rat everted gut sacs and an in situ closed-loop recirculation method. We extracted lumbrokinase from Eisenia andrei, and then raised polyclonal antibody against lumbrokinase. Fibrinolytic activity and proteolytic activity in the serosal side of rat everted gut sacs incubated with lumbrokinase showed dose- and time-dependent patterns. Immunological results obtained by western blotting serosal side solution using rat everted gut sacs method showed that lumbrokinase proteins between 33.6 and 54.7 kDa are absorbed mostly by the intestinal epithelium. Furthermore, MALDI-TOF mass spectrometric analysis of plasma fractions obtained by in situ recirculation method confirmed that lumbrokinase F1 is absorbed into blood. These results support the notion that lumbrokinase can be absorbed from mucosal lumen into blood by oral administration.

Comparative Study of Enzyme Activity and Stability of Bovine and Human Plasmins in Electrophoretic Reagents, β-mercaptoethanol, DTT, SDS, Triton X-100, and Urea

Effects of common electrophoretic reagents, reducing agents (beta-mercaptoethanol [BME] and DTT), denaturants (SDS and urea), and non-ionic detergent (Triton X-100), on the activity and stability of bovine plasmin (b-pln) and human plasmin (h-pln) were compared. In the presence of 0.1% SDS (w/v), all reagents completely inhibited two plns, whereas SDS (1%) and urea (1 M) denatured plns recovered their activities after removal of SDS by treatment of 2.5% Triton X-100 (v/v). However, reducing agents (0.1 M of BME and DTT) treated plns did not restore their activities. Based on a fibrin zymogram gel, five (from b-pln) and four (from h-pln) active fragments were resolved. Two plns exhibited unusual stability in concentrated SDS and Triton X-100 (final 10%) and urea (final 6 M) solutions. Two bands, heavy chain-2 (HC-2) and cleaved heavy chain-2 (CHC-2), of b-pln were completely inhibited in 0.5% SDS or 3 M urea, whereas no significant difference was found in h-pln. Interestingly, 50 kDa (cleaved heavy chain-1, CHC-1) of b-pln and two fragments, 26 kDa (light chain, LC) and 29 kDa (microplasmin, MP), of h-pln were increased by SDS in a concentration dependent manner. We also found that the inhibition of SDS against both plns was reversible.

Large-scale and effective screening of Korean medicinal plants for inhibitory activity on matrix metalloproteinase-9

Matrix metalloproteinase-9 (MMP-9) degrades type IV collagen constituting the major structural component of the basement membrane and extra cellular membrane. The enzymatic activity is found to be elevated in tumor tissues. With the aim of finding novel MMP-9 inhibitors from natural products, 87 extracts of oriental medicinal herbs, which are used as prescriptions for cancer treatment in traditional Korean medicine, were screened for their inhibitory activities towards MMP-9. It was found that most of the hexane and chloroform fractions as well as water extracts showed a weak inhibitory effect on MMP-9 activity at a concentration of 100mug/ml. However, a strong inhibition was found in the butanol fractions of Cinnamomum cassia PRESL, Magnolia obovata THUEB., Magnolia officinalis REHD. et WILS., Magnolia officinalis REHD. et WILS. var. biloba REHD. et WILS., and Euonymus alatus (THUNB.) SIEB. with inhibitory activity (>90%) at a concentration of 100 microg/ml.

Correlation between plasma levels of matrix metalloproteinase (MMP)-9 /MMP-2 ratio and alpha-fetoproteins in chronic hepatitis carrying hepatitis B virus

BACKGROUND

Matrix metalloproteases (MMP) and alpha-fetoproteins (AFP) are involved in hepatitis B virus (HBV)-induced chronic hepatitis. In the present study, we have determined the correlation between the MMP-9/MMP-9 ratio and AFP levels in the serum of patients during chronic viral B hepatitis.

METHODS

Twenty-eight healthy individuals (18 men and 10 women) with a mean age of 36.3 years (range 23-58 years) and 50 patients (42 men, 8 women) with a mean age of 39.7 years (range 22-61 years) participated in the study. Forty-eight participants had HBV and the remaining two were either hepatitis G virus (HGV) or hepatitis C virus (HCV) carriers. Values of patients were compared with those obtained from 12 blood donor controls (5 men, 7 women), mean age 36 years (range 21-46 years). Patients' sera were subjected to examination of hepatitis B surface (HBs) and hepatitis B early (Hbe) antigen, SGOT, SGPT, AFP, MMP-2 and MMP-9. Serum levels of MMP-2 and MMP-9 activities were measured by a zymogram protease assay and densitometric measurement. The ratios of MMP-9 to MMP-2 were calculated by dividing the densitometric results.

RESULTS

Compared with the healthy controls, the mean serum concentrations of MMP-2 were slightly increased in the chronic HBV patients. In contrast, compared with the healthy controls, the mean serum concentrations of MMP-9 were significantly increased in the chronic HBV patients. When the ratios of the MMP-9/MMP-2 and amounts of the serum AFP were compared, a specific correlation between these two parameters was observed. Higher amounts of AFP were detected in the patients with a low ratio of MMP-9/MMP-2. Patients with hepatocellular carcinoma (HCC) and cirrhosis showed relatively low MMP-9/MMP-2 ratios in chronic hepatitis B. In addition, AFP levels of HCC and cirrhosis were higher than in chronic HBV patients.

CONCLUSIONS

These results indicate that the AFP level and ratio of MMP-9 and MMP-2 is highly correlated in chronic HBV-induced hepatitis. Because the serum MMP activities were significantly varied between each stage of AFP production in liver disease, an individual profile of these parameters might serve as an easy accessing serum marker to monitor the progression of liver disease.

Inhibitory effect of methanol extract of Euonymus alatus on matrix metalloproteinase-9

Various extracts prepared from stems of Euonymus alatus were tested for cytotoxic activity on human hepatocellular carcinoma cell line, Hep3B cells using the XTT assay method. Also, the extracts were investigated the inhibitory effects on matrix metalloproteinase (MMP)-9 activity using gelatin zymography. The methanol extract, hexane and ethyl acetate fraction exhibited weak cytotoxic activity (IC(50) of >100 microg/ml). However, butanol (IC(50)=65 microg/ml) and chloroform (IC(50)=85 microg/ml) fraction exhibited strongly cytotoxic activity. Gelatin zymography showed that the Hep3B cells secreted matrix metalloproteinase (MMP), probably including MMP-9, which may be involved in tumor cell invasion and metastasis. The butanol fraction showed stronger inhibitory effect of proteolytic activity than other fractions. Also, the butanol fraction was able to decrease the proteolytic activity of MMP-9 in a concentration-dependent manner on zymography. These results suggest that the butanol fraction from E. alatus has highly inhibitory effect on MMP-9 in comparatively low cytotoxicity.