scholarly journals Identification and characterisation of gut proteases in the fig tree skeletoniser moth, Choreutis nemorana Hübner (Lepidoptera: Choreutidae)

2013 ◽  
Vol 49 (No. 1) ◽  
pp. 19-26 ◽  
Author(s):  
M. Gholamzadeh Chitgar ◽  
M. Ghadamyari ◽  
M. Sharifi
Keyword(s):  
Digestive System ◽  
Proteinase Inhibitors ◽  
Cysteine Proteases ◽  
Inhibitory Effect ◽  
Biochemical Properties ◽  
Peptide Substrates ◽  
Proteolytic Activities ◽  
Tryptic Activity ◽  
Fig Tree ◽  
Sulfonyl Fluoride

The biochemical properties of proteases from the digestive system of the fig tree skeletonizer moth, Choreutis nemorana, were determined. Gut extracts of C. nemorana larvae were analysed using different specific peptide substrates and proteinase inhibitors. The optimal pH and temperature for proteolytic activities using azocasein as substrate were obtained as pH 11 and 45&deg;C, respectively. In the case of N-benzoyl-l-arg-p-nitroanilide as substrate, the enzyme showed the maximum tryptic activity at pH 11. The kinetic parameters of trypsin-like proteases indicated that the K<sub>m</sub> and V<sub>max</sub> values of trypsin in the gut of C. nemorana were 0.157 &plusmn; 0.006mM and 0.188 &plusmn; 0.005 &micro;mol/min/mgprotein. Using specific proteolytic inhibitors, the inhibitors including phenyl methane sulfonyl fluoride, N-p-tosyl-l-lys chloromethyl ketone and ethylene diamine tetraacetic acid showed the greatest inhibitory effect on total proteolytic activity. These results indicated that serine proteinases accounted for the major proteases in the gut of C. nemorana. Inhibition assays and zymogram analysis showed that only small amounts of cysteine proteases are present in the digestive system of C. nemorana.

scholarly journals In Vitro α-Glucosidase and α-Amylase Inhibitory Activities of Free and Bound Phenolic Extracts from the Bran and Kernel Fractions of Five Sorghum Grain Genotypes

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1301
Author(s):  
Yun Xiong ◽  
Ken Ng ◽  
Pangzhen Zhang ◽  
Robyn Dorothy Warner ◽  
Shuibao Shen ◽  
...  
Keyword(s):  
Digestive System ◽  
Inhibitory Concentration ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
Phenolic Contents ◽  
Inhibitory Activities ◽  
Sorghum Grain ◽  
Global Health Challenge ◽  
Phenolic Extracts

Diabetes is a global health challenge. Currently, an effective treatment for diabetes is to reduce the postprandial hyperglycaemia by inhibiting the carbohydrate hydrolysing enzymes in the digestive system. In this study, we investigated the in vitro α-glucosidase and α-amylase inhibitory effects of free and bound phenolic extracts, from the bran and kernel fractions of five sorghum grain genotypes. The results showed that the inhibitory effect of sorghum phenolic extracts depended on the phenolic concentration and composition. Sorghum with higher phenolic contents generally had higher inhibitory activity. Among the tested extracts, the brown sorghum (IS131C)-bran-free extract (BR-bran-free, half-maximal inhibitory concentration (IC50) = 18 ± 11 mg sorghum/mL) showed the strongest inhibition against α-glucosidase which was comparable to that of acarbose (IC50 = 1.39 ± 0.23 mg acarbose/mL). The red sorghum (Mr-Buster)-kernel-bound extract (RM-kernel-bound, IC50 = 160 ± 12 mg sorghum/mL) was the most potent in inhibiting α-amylase but was much weaker compared to acarbose (IC50 = 0.50 ± 0.03 mg acarbose/mL).

scholarly journals The Pharmacological Activity, Biochemical Properties, and Pharmacokinetics of the Major Natural Polyphenolic Flavonoid: Quercetin

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 374 ◽  
Author(s):  
Gaber El-Saber Batiha ◽  
Amany Magdy Beshbishy ◽  
Muhammad Ikram ◽  
Zohair S. Mulla ◽  
Mohamed E. Abd El-Hack ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Biological Activities ◽  
Inhibitory Effect ◽  
Biochemical Properties ◽  
Beneficial Effects ◽  
Natural Substances ◽  
Current Review ◽  
Flavonoid Quercetin ◽  
Small Intestines ◽  
The Brain

Flavonoids are a class of natural substances present in plants, fruits, vegetables, wine, bulbs, bark, stems, roots, and tea. Several attempts are being made to isolate such natural products, which are popular for their health benefits. Flavonoids are now seen as an essential component in a number of cosmetic, pharmaceutical, and medicinal formulations. Quercetin is the major polyphenolic flavonoid found in food products, including berries, apples, cauliflower, tea, cabbage, nuts, and onions that have traditionally been treated as anticancer and antiviral, and used for the treatment of allergic, metabolic, and inflammatory disorders, eye and cardiovascular diseases, and arthritis. Pharmacologically, quercetin has been examined against various microorganisms and parasites, including pathogenic bacteria, viruses, and Plasmodium, Babesia, and Theileria parasites. Additionally, it has shown beneficial effects against Alzheimer’s disease (AD), and this activity is due to its inhibitory effect against acetylcholinesterase. It has also been documented to possess antioxidant, antifungal, anti-carcinogenic, hepatoprotective, and cytotoxic activity. Quercetin has been documented to accumulate in the lungs, liver, kidneys, and small intestines, with lower levels seen in the brain, heart, and spleen, and it is extracted through the renal, fecal, and respiratory systems. The current review examines the pharmacokinetics, as well as the toxic and biological activities of quercetin.

Study of the Proteolytic Activity of the Tropical Legume Crotalaria spectabilis

2012 ◽  
Vol 67 (9-10) ◽  
pp. 495-509 ◽  
Author(s):  
Juliana da Silva Pacheco ◽  
Raquel Elisa da Silva-Lopez
Keyword(s):  
Proteolytic Activity ◽  
Serine Proteases ◽  
Ph Value ◽  
Cysteine Proteases ◽  
Leaf Extracts ◽  
Serine Protease Activity ◽  
Proteolytic Activities ◽  
Low Levels ◽  
Crotalaria Spectabilis

The characterization of legume proteases contributes to the understanding of the physiology of plants and their interaction with the environment. Thirteen extracts from various parts of Crotalaria spectabilis were made using different extraction systems. The highest protein content was found in seeds, and the most pronounced proteolytic activity was observed in leaf extracts, with an optimal pH value in the alkaline range. Proteases in extracts from roots, stems, and fl owers were active in various pH ranges. Proteases in all extracts were maximally active between 30 °C and 60 °C and were thermostable (24 h, 60 °C). Hemoglobin, bovine serum albumin, casein, and gelatin were hydrolyzed by C. spectabilis extracts in different ways. The highest serine protease activity was found in leaves. Seeds contained high levels of serine proteases and low levels of cysteine proteases. Flowers, roots, and stems contained different levels of serine, aspartic, and metalloproteases, respectively. The proteolytic activities in extracts were modulated by cations and oxidants to various degrees. C. spectabilis proteases are differentially expressed in distinctive organs, and their stability against heat and oxidants makes this plant an important source of stable proteases

A Proteasome Specific Binding Assay for Quantitation of Constitutive and Immunoproteasome Active Sites.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2472-2472
Author(s):  
Mark K. Bennett ◽  
Monette A. Aujay ◽  
Tonia J. Buchholz ◽  
Susan D. Demo ◽  
Guy J. Laidig ◽  
...  
Keyword(s):  
Active Sites ◽  
Antigen Processing ◽  
Specific Binding ◽  
Peripheral Blood Mononuclear ◽  
Peptide Substrates ◽  
Enzyme Preparations ◽  
Proteolytic Activities ◽  
Fluorogenic Peptide

Abstract The ubiquitin-proteasome pathway constitutes a major intracellular system for protein degradation. Substrates for this pathway include misfolded or unassembled proteins as well as short-lived regulatory proteins that play key roles in signaling and proliferative pathways. The majority of cell types express the standard, or “constitutive”, form of the proteasome, while cells of the immune system also express the immunoproteasome, a form of the proteasome that contributes to class I major histocompatibility complex restricted antigen processing. Non-immune cells can also express immunoproteasome in response to interferon gamma exposure. The immunoproteasome retains the same structural subunits as the constitutive proteasome but has three different catalytic subunits. The catalytic activities of both forms of the proteasome have been traditionally characterized with purified enzyme preparations and fluorogenic peptide substrates. Such fluorogenic peptide substrates suffer from two characteristics that limit their utility in measuring proteasome activities in complex cell or tissue lysates: 1) they cannot distinguish proteasome activities from other proteolytic activities within the lysate; and 2) they can not distinguish between constitutive and immunoproteasome activities. We have developed an ELISA-based proteasome-specific binding (PSB) assay that can detect and quantify the chymotryptic-like proteasome active sites of the beta-5 constitutive proteasome subunit and the LMP7 immunoproteasome subunit. The assay utilizes a biotin-modified peptide epoxyketone probe that covalently and irreversibly interacts with the active site threonine present in catalytic proteasome subunits. Once bound to the probe, the labeled subunits are recovered on streptavidin-conjugated beads and detected with subunit-specific antibodies. The PSB assay is both quantitative and sensitive. We have demonstrated that the assay is capable of measuring constitutive proteasome and immunoproteasome binding activity in human whole blood and peripheral blood mononuclear cell preparations, respectively. In experiments with the epoxyketone-based proteasome inhibitor PR-171, the dose response for inhibition of the PSB assay is equivalent to that measured with a conventional fluorogenic peptide proteasome substrate. In addition, the PSB assay can effectively measure the level of PR-171 mediated inhibition of both the constitutive and immunoproteasome in the RPMI-8226 multiple myeloma cell line that co-expresses both proteasome types. Thus, the PSB assay overcomes the limitations of conventional fluorogenic substrate-based proteasome activity assays when applied to cell or tissue lysates that contain multiple proteolytic activities or mixtures of constitutive and immunoproteasomes. Potential applications of the PSB assay include the measurement of the pharmacodynamic response to proteasome inhibitors and the evaluation of constitutive vs. immunoproteasome selectivity of inhibitors both in vitro and in vivo.

Protease activities of Acanthamoeba polyphaga and Acanthamoeba castellanii

2006 ◽  
Vol 52 (1) ◽  
pp. 16-23 ◽  
Author(s):  
José de Jesús Serrano-Luna ◽  
Isaac Cervantes-Sandoval ◽  
Jesús Calderón ◽  
Fernando Navarro-García ◽  
Victor Tsutsumi ◽  
...  
Keyword(s):  
Protease Activity ◽  
Serine Proteases ◽  
Biochemical Characterization ◽  
Acanthamoeba Castellanii ◽  
Cysteine Proteases ◽  
Skin Lesions ◽  
Sds Page ◽  
Serine Protease Family ◽  
Proteolytic Activities ◽  
Amoebic Keratitis

Acanthamoeba spp. are free-living amoebae that cause amoebic granulomatous encephalitis, skin lesions, and ocular amoebic keratitis in humans. Several authors have suggested that proteases could play a role in the pathogenesis of these diseases. In the present work, we performed a partial biochemical characterization of proteases in crude extracts of Acanthamoeba spp. and in conditioned medium using 7.5% SDS–PAGE copolymerized with 0.1% m/v gelatin as substrate. We distinguished a total of 17 bands with proteolytic activity distributed in two species of Acanthamoeba. The bands ranged from 30 to 188 kDa in A. castellanii and from 34 to 144 kDa in A. polyphaga. Additionally, we showed that the pattern of protease activity differed in the two species of Acanthamoeba when pH was altered. By using protease inhibitors, we found that the proteolytic activities belonged mostly to the serine protease family and secondly to cysteine proteases and that the proteolytic activities from A. castellanii were higher than those in A. polyphaga. Furthermore, aprotinin was found to in hibit crude extract protease activity on Madin–Darby canine kidney (MDCK) monolayers. These data suggest that protease patterns could be more complex than previously reported.Key words: Acanthamoeba spp., amoebic keratitis, serine proteases, cysteine proteases, cytopathic effect.

Some characteristics of extracellular proteases produced by members of the Chytridiales and the Spizellomycetales (Chytridiomycetes)

1994 ◽  
Vol 40 (2) ◽  
pp. 106-112 ◽  
Author(s):  
Thomas Krarup ◽  
Lauritz W. Olson ◽  
Hans Peter Heldt-Hansen
Keyword(s):  
Proteolytic Activity ◽  
Isoelectric Focusing ◽  
Serine Proteases ◽  
Proteolytic Enzymes ◽  
Complex Compounds ◽  
Extracellular Proteases ◽  
Peptide Substrates ◽  
Proteolytic Activities ◽  
Selection Of

The extracellular proteolytic enzymes of eight saprophytic, eucarpic, and monocentric isolates from two genera of the order Spizellomycetales and from one genus of the order Chytridiales (Chytridiomycetes) have been partially characterized. The isolectric points of the proteases were estimated from zymograms and demonstrate the existence of three types of proteolytic activity in most isolates. The proteases were tested against synthetic chromogenic peptide substrates and a selection of cations and more complex compounds, and the results suggest that parts of the extracellular proteolytic activities are due to proteases from two groups: the Ca2+ stabilized proteases and the alkaline serine proteases.Key words: serine proteases, metalloproteases, Chytridiomycetes, isoelectric focusing, chromogenic peptide substrates.

scholarly journals Expression and Functional Characteristics of Calpain 3 Isoforms Generated through Tissue-Specific Transcriptional and Posttranscriptional Events

1999 ◽  
Vol 19 (6) ◽  
pp. 4047-4055 ◽  
Author(s):  
Muriel Herasse ◽  
Yasuko Ono ◽  
Françoise Fougerousse ◽  
Ei-ichi Kimura ◽  
Daniel Stockholm ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Calcium Binding ◽  
Biochemical Properties ◽  
Therapeutic Strategies ◽  
Biological Functions ◽  
Truncated Protein ◽  
Binding Domains ◽  
Calpain 3 ◽  
Its Gene ◽  
Proteolytic Activities

ABSTRACT Calpain 3 is a nonlysosomal cysteine protease whose biological functions remain unknown. We previously demonstrated that this protease is altered in limb girdle muscular dystrophy type 2A patients. Preliminary observations suggested that its gene is subjected to alternative splicing. In this paper, we characterize transcriptional and posttranscriptional events leading to alterations involving the NS, IS1, and IS2 regions and/or the calcium binding domains of the mouse calpain 3 gene (capn3). These events can be divided into three groups: (i) splicing of exons that preserve the translation frame, (ii) inclusion of two distinct intronic sequences between exons 16 and 17 that disrupt the frame and would lead, if translated, to a truncated protein lacking domain IV, and (iii) use of an alternative first exon specific to lens tissue. In addition, expression of these isoforms seems to be regulated. Investigation of the proteolytic activities and titin binding abilities of the translation products of some of these isoforms clearly indicated that removal of these different protein segments affects differentially the biochemical properties examined. In particular, removal of exon 6 impaired the autolytic but not fodrinolytic activity and loss of exon 16 led to an increased titin binding and a loss of fodrinolytic activity. These results are likely to impact our understanding of the pathophysiology of calpainopathies and the development of therapeutic strategies.

scholarly journals α-1-Anti-trypsin, an inhibitor of renin

1976 ◽  
Vol 153 (2) ◽  
pp. 505-507 ◽  
Author(s):  
S Scharpé ◽  
M Eid ◽  
W Cooreman ◽  
A Lauwers
Keyword(s):  
Human Plasma ◽  
Competitive Inhibition ◽  
Proteinase Inhibitors ◽  
Competitive Inhibitor ◽  
Inhibitory Effect ◽  
Renin Activity ◽  
Pig Kidney ◽  
Naturally Occurring ◽  
The Hill

A naturally occurring competitive inhibitor of pig kidney renin has been identified in human plasma. The inhibitor was shown to be α-1 anti-trypsin and the effect in vitro on the renin activity was examined. The slope in the Hill plot is compatible with the assumption of one-site competitive inhibition. Other proteinase inhibitors, such as α-2-macroglobulin and C1 inactivator, however, have no inhibitory effect on the renin-angiotensinogen reaction.

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