scholarly journals Anti-α-Glucosidase Activity by a Protease from Bacillus licheniformis

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 691 ◽  
Author(s):  
Chien Doan ◽  
Thi Tran ◽  
Minh Nguyen ◽  
Van Nguyen ◽  
Anh Nguyen ◽  
...  

Anti-α-glucosidase (AAG) compounds have received great attention due to their potential use in treating diabetes. In this study, Bacillus licheniformis TKU004, an isolated bacterial strain from Taiwanese soil, produced AAG activity in the culture supernatant when squid pens were used as the sole carbon/nitrogen (C/N) source. The protein TKU004P, which was isolated from B. licheniformis TKU004, showed stronger AAG activity than acarbose, a commercial anti-diabetic drug (IC50 = 0.1 mg/mL and 2.02 mg/mL, respectively). The molecular weight of TKU004P, determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), was 29 kDa. High-performance liquid chromatography (HPLC) analysis showed that TKU004P may be a protease that demonstrates AAG activity by degrading yeast α-glucosidase. Among the four chitinous sources of C/N, TKU004P produced the highest AAG activity in the culture supernatant when shrimp head powder was used as the sole source (470.66 U/mL). For comparison, 16 proteases, were investigated for AAG activity but TKU004P produced the highest levels. Overall, the findings suggest that TKU004P could have applications in the biochemical and medicinal fields thanks to its ability to control the activity of α-glucosidase.

2014 ◽  
Vol 989-994 ◽  
pp. 1020-1024
Author(s):  
Nan Nan ◽  
Xi Jing Liu

Radix Isatidis is a traditional Chinese medicine for treatment of influenza and inflammation in China. In this paper, in order to study the degradation situation of Radix Isatidis polypeptide in artificial gastrointestinal environment, the SDS-PAGE (Sodium dodecyl sulfate-polyacrylamide gel electrophoresis) method was used to detect the degradation of Radix Isatidis polypeptide in artificial intestinal juice and gastric juice, and it showed that Radix Isatidis peptides could be degradated to different degrees. HPLC (High Performance Liquid Chromatography) was used to determine the change of peptides degradation, and it indicated that free amino acid levels did not change significantly. The result after degradation was also detected by BCA method, and it showed that there were still a large number of polypeptides in the liquid. From this experiment we can come to this conclusion that Radix Isatidis polypeptides in artificial gastrointestinal juice mostly degraded into a series of different molecular weight peptides.


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3235
Author(s):  
Min Zuo ◽  
Xiao-xiao Liu ◽  
Di Liu ◽  
Hang-yun Zhao ◽  
Lu-lu Xuan ◽  
...  

Semen Allii Fistulosi (PSAF) is the seed of Allium fistulosum L. of the Liliaceae family. The purpose of this study was to extract, characterize, and evaluate the antioxidant activity in vitro of proteins. Using single factor and orthogonal design, the optimum conditions of extraction were determined to be as follows: extraction time 150 min, pH 8.5, temperature 60 °C, and ratio (v/w, mL/g) of extraction solvent to raw material 35. The isoelectric point of the pH was determined to be about 4.4 and 10.2, by measuring the protein content of PSAF solutions at different pH values. The amino acid composition of PSAF was determined by high performance liquid chromatography (HPLC), and the results suggested that the species of amino acids contained in the PSAF was complete. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS–PAGE) analysis showed the molecular weight was mainly between 40 and 55 kDa, and Fourier-transform infrared spectroscopy (FTIR) characterized prevalent protein absorption peaks. PSAF exhibited potent scavenging activities against DPPH assays, via targeting of hydroxyl and superoxide radicals, while chelating Fe2+ activity and demonstrating weak reducing power. This work revealed that PSAF possessed potential antioxidant activity in vitro, suggesting potential for use of PSAF as a natural antioxidant.


2007 ◽  
Vol 189 (7) ◽  
pp. 2660-2666 ◽  
Author(s):  
Vandana P. Swetha ◽  
Aditya Basu ◽  
Prashant S. Phale

ABSTRACT Pseudomonas sp. strain C4 metabolizes carbaryl (1-naphthyl-N-methylcarbamate) as the sole source of carbon and energy via 1-naphthol, 1,2-dihydroxynaphthalene, and gentisate. 1-Naphthol-2-hydroxylase (1-NH) was purified 9.1-fold to homogeneity from Pseudomonas sp. strain C4. Gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the enzyme is a homodimer with a native molecular mass of 130 kDa and a subunit molecular mass of 66 kDa. The enzyme was yellow, with absorption maxima at 274, 375, and 445 nm, indicating a flavoprotein. High-performance liquid chromatography analysis of the flavin moiety extracted from 1-NH suggested the presence of flavin adenine dinucleotide (FAD). Based on the spectral properties and the molar extinction coefficient, it was determined that the enzyme contained 1.07 mol of FAD per mol of enzyme. Although the enzyme accepts electrons from NADH, it showed maximum activity with NADPH and had a pH optimum of 8.0. The kinetic constants Km and V max for 1-naphthol and NADPH were determined to be 9.6 and 34.2 μM and 9.5 and 5.1 μmol min−1 mg−1, respectively. At a higher concentration of 1-naphthol, the enzyme showed less activity, indicating substrate inhibition. The Ki for 1-naphthol was determined to be 79.8 μM. The enzyme showed maximum activity with 1-naphthol compared to 4-chloro-1-naphthol (62%) and 5-amino-1-naphthol (54%). However, it failed to act on 2-naphthol, substituted naphthalenes, and phenol derivatives. The enzyme utilized one mole of oxygen per mole of NADPH. Thin-layer chromatographic analysis showed the conversion of 1-naphthol to 1,2-dihydroxynaphthalene under aerobic conditions, but under anaerobic conditions, the enzyme failed to hydroxylate 1-naphthol. These results suggest that 1-NH belongs to the FAD-containing external flavin mono-oxygenase group of the oxidoreductase class of proteins.


Author(s):  
Frederico Guilherme Coutinho Abath ◽  
Luís Carlos de Sousa Ferreira

In the present study three techniques for obtaining outer membrane enriched fractions from Yersinia pestis were evaluated. The techniques analysed were: differential solubilization of the cytoplasmic membrane with Sarkosyl or Triton X-100, and centrifugation in sucrose density gradients. The sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of outer membrane isolated by the different methods resulted in similar protein patterns. The measurement of NADH-dehydrogenase and succinate dehydrogenase (inner membrane enzymes) indicated that the outer membrane preparations obtained by the three methods were pure enough for analytical studies. In addition, preliminary evidences on the potential use of outer membrane proteins for the identification of geographic variants of Y. pestis wild isolates are presented.


1993 ◽  
Vol 265 (5) ◽  
pp. G894-G902 ◽  
Author(s):  
D. D. Stump ◽  
S. L. Zhou ◽  
P. D. Berk

A relationship between plasma membrane fatty acid binding protein (FABPpm), a putative membrane transporter for long-chain fatty acids, and the mitochondrial isoform of aspartate aminotransferase (m-AspAT) has been reported. Accordingly, we have compared the chemical and immunological properties of rat liver m-AspAT with those of rat liver FABPpm isolated by two procedures: 1) detergent solubilization of the membranes followed by purification via fatty acid affinity chromatography (FABP-1) or 2) salt extraction of the membranes and subsequent purification by high-performance liquid chromatography (HPLC; FABP-2). Comparison of the three protein preparations revealed no differences with respect to NH2-terminal amino acid sequence, amino acid composition, peptides from tryptic digests, AspAT enzymatic activity, isoelectric point, mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), retention on five different HPLC columns, and immunoprecipitation and immunoblotting of SDS-PAGE separated proteins with polyclonal antisera. Examination of the proteins by nondenaturing PAGE showed a consistent second band in FABP-1 and FABP-2 not always present in m-AspAT. However, whenever present, this band was immunoreactive with antibodies to both m-AspAT and FABP-1. Hence, FABP-1 and FABP-2 are indistinguishable from one another. They are also at least closely related, if not identical, to m-AspAT.


Blood ◽  
1990 ◽  
Vol 75 (8) ◽  
pp. 1673-1678 ◽  
Author(s):  
O Wilhelm ◽  
R Hafter ◽  
A Henschen ◽  
M Schmitt ◽  
H Graeff

Abstract The aim of this study was to evaluate the type of enzymes involved in tumor-associated fibrinolysis of the stroma component fibrin in ovarian cancer patients. For this purpose, the high-molecular-mass fibrin degradation products (HMM-XDP) were isolated from malignant ascitic fluid by protamine sulfate precipitation and further purified by gel filtration and acid precipitation. After reduction with 2- mercaptoethanol, the peptide chain components were separated by reverse- phase high-performance liquid chromatography (RP-HPLC). The nature of these components was elucidated by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and N-terminal amino acid sequence analysis and compared with fibrin-derived fragments formed in vitro. The results indicate that plasmin is the essential protease involved in the degradation of the stroma-derived fibrin portion found in ovarian cancer ascites.


Blood ◽  
1988 ◽  
Vol 71 (2) ◽  
pp. 480-487
Author(s):  
N Yoshida ◽  
K Ota ◽  
M Moroi ◽  
M Matsuda

A gamma-chain variant with an apparently higher molecular weight than the normal gamma-chain was detected in a new congenital abnormal fibrinogen with impaired polymerization of the fibrin monomer and with normal release of fibrinopeptides A and B in a 51-year-old male. Purified fibrinogen analyzed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under the reduced condition in the system of Laemmli contained two protein bands in the gamma-chain region (molecular weight, 50,500 as compared with 50,000 for the normal), both with normal crosslinking ability. The presence of two types of gamma- chains was more clearly detected when reduced and carboxymethylated fibrinogen was analyzed by SDS-PAGE or when reduced fragment D2 was analyzed on SDS-PAGE followed by Western blotting, and identified by positive staining for anti gamma-chain monoclonal antibody. Cyanogen bromide- or lysylendopeptidase-cleavage of purified gamma-chains analyzed on reverse-phase high performance liquid chromatography showed the decrease of one peptide compared with the normal and the appearance of an abnormal peptide peak. Amino acid sequence analysis demonstrated that the gamma arginine-275 of gamma-chain variant was replaced by a cysteine. These data suggest that some regions or conformations containing gamma 275 will affect the polymerization of fibrin monomers. The propositus' two daughters had the same abnormal fibrinogen. This unique inherited abnormal fibrinogen was designated as fibrinogen Tochigi, and the gamma-chain variant as gamma Tochigi.


Blood ◽  
1990 ◽  
Vol 75 (8) ◽  
pp. 1659-1663 ◽  
Author(s):  
S Bantia ◽  
WR Bell ◽  
CV Dang

Fibrinogen Baltimore III, a congenital abnormal fibrinogen with impaired fibrin monomer polymerization, displays a normal gamma-chain and a gamma-variant that has an apparently lower relative molecular weight (mol wt) than normal on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Reverse phase high-performance liquid chromatography (HPLC) analysis of the lysyl endopeptidase digest of the purified gamma-chains of fibrinogen Baltimore III revealed the presence of a peptide that is not found in the digest of the normal fibrinogen gamma-chain. Amino acid sequence analysis of this peptide indicated that the gamma-chain residue 308, asparagine, is replaced by isoleucine. Concanavalin A bound both normal and variant gamma-chains of fibrinogen Baltimore III, indicating that the carbohydrate moiety is not altered and is not responsible for the increase in electrophoretic mobility of the Baltimore III gamma-chain. This study suggests that the integrity of gamma Asn308 is critical for fibrin monomer polymerization, since alteration to either a basic (fibrinogen Kyoto I, Asn----Lys) or hydrophobic (Asn----Ile) residue results in significantly delayed polymerization of fibrinogen to fibrin.


Blood ◽  
1990 ◽  
Vol 75 (8) ◽  
pp. 1659-1663 ◽  
Author(s):  
S Bantia ◽  
WR Bell ◽  
CV Dang

Abstract Fibrinogen Baltimore III, a congenital abnormal fibrinogen with impaired fibrin monomer polymerization, displays a normal gamma-chain and a gamma-variant that has an apparently lower relative molecular weight (mol wt) than normal on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Reverse phase high-performance liquid chromatography (HPLC) analysis of the lysyl endopeptidase digest of the purified gamma-chains of fibrinogen Baltimore III revealed the presence of a peptide that is not found in the digest of the normal fibrinogen gamma-chain. Amino acid sequence analysis of this peptide indicated that the gamma-chain residue 308, asparagine, is replaced by isoleucine. Concanavalin A bound both normal and variant gamma-chains of fibrinogen Baltimore III, indicating that the carbohydrate moiety is not altered and is not responsible for the increase in electrophoretic mobility of the Baltimore III gamma-chain. This study suggests that the integrity of gamma Asn308 is critical for fibrin monomer polymerization, since alteration to either a basic (fibrinogen Kyoto I, Asn----Lys) or hydrophobic (Asn----Ile) residue results in significantly delayed polymerization of fibrinogen to fibrin.


1996 ◽  
Vol 42 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Edivaldo Ximenes Ferreira Filho

The thermophilic fungus Humicola grisea var. thermoidea produced β-glucosidase activity when grown in a solid-state culture on wheat bran as carbon source. A β-glucosidase was purified to apparent homogeneity by ultrafiltration, gel filtration chromatography on Sephacryl S-100, and ion-exchange chromatography on S-Sepharose, as judged by sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS–PAGE) on a 12.5% (w/v) slab gel. The enzyme had a molecular mass of 82 and 156 kDa, as estimated by SDS–PAGE and gel filtration on a high performance liquid chromatographic column, respectively, suggesting that the native enzyme may consist of two identical subunits. The purified enzyme was thermostable at 60 °C for 1 h with a half-life of 15 min at 65 °C, and displayed optimum activity at 60 °C and a pH range of 4.0–4.5. The Kmand Vmaxvalues for p-nitrophenyl β-D-glucopyranoside were determined to be 0.316 mM and 0.459 IU∙mL−1, respectively. D-Glucose, D-gluconic acid lactone, Hg2+, Cu2+, and Mn2+inhibited β-glucosidase activity. The enzyme activity was competitively inhibited by D-glucose (Ki = 0.6 mM). The purified enzyme was very active against cellobiose and p-nitrophenyl β-D-glucopyranoside.Key words: Humicola, β-glucosidase, purification, characterization.


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