scholarly journals WPK5, a Novel Kunitz-Type Peptide from the Leech Whitmania pigra Inhibiting Factor XIa, and Its Loop-Replaced Mutant to Improve Potency

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1745
Author(s):  
Yi-Zheng Zheng ◽  
Xiao-Ru Ji ◽  
Yun-Yang Liu ◽  
Shuai Jiang ◽  
Xiang-Ying Yu ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Bleeding Risk ◽  
Blood Sucking ◽  
Ic50 Value ◽  
Factor Xia ◽  
Kunitz Type ◽  
Loop 2 ◽  
Whitmania Pigra

Kunitz-type proteins or peptides have been found in many blood-sucking animals, but the identity of them in leeches remained elusive. In the present study, five Kunitz-type peptides named WPK1-WPK5 were identified from the leech Whitmania pigra. Recombinant WPK1-WPK5 were expressed in Pichia pastoris GS115, and their inhibitory activity against Factor XIa (FXIa) was tested. WPK5 showed inhibitory activity against FXIa with an IC50 value of 978.20 nM. To improve its potency, the loop replacement strategy was used. The loop 1 (TGPCRSNLER) and loop 2 (QYGGC) in WPK5 were replaced by loop 1 (TGPCRAMISR) and loop 2 (FYGGC) in PN2KPI, respectively, and the resulting peptide named WPK5-Mut showed an IC50 value of 8.34 nM to FXIa, which is about 100-fold the potency of FXIa compared to that of WPK5. WPK5-Mut was further evaluated for its extensive bioactivity in vitro and in vivo. It dose-dependently prolonged APTT on both murine plasma and human plasma, and potently inhibited FeCl3-induced carotid artery thrombosis in mice at a dose of 1.5 mg/kg. Additionally, WPK5-Mut did not show significant bleeding risk at a dose of 6 mg/kg. Together, these results showed that WPK5-Mut is a promising candidate for the development of an antithrombotic drug.

scholarly journals DAKS1, a Kunitz Scaffold Peptide from the Venom Gland of Deinagkistrodon acutus Prevents Carotid-Artery and Middle-Cerebral-Artery Thrombosis via Targeting Factor XIa

2021 ◽  
Vol 14 (10) ◽  
pp. 966
Author(s):  
Zhiping Jia ◽  
Yunyang Liu ◽  
Xiaoru Ji ◽  
Yizheng Zheng ◽  
Zhengyang Li ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Inhibitory Activity ◽  
Bleeding Risk ◽  
Venom Gland ◽  
Artery Occlusion ◽  
Factor Xia ◽  
Deinagkistrodon Acutus

Scaffold-based peptides (SBPs) are fragments of large proteins that are characterized by potent bioactivity, high thermostability, and low immunogenicity. Some SBPs have been approved by the FDA for human use. In the present study, we developed SBPs from the venom gland of Deinagkistrodon acutus (D. acutus) by combining transcriptome sequencing and Pfam annotation. To that end, 10 Kunitz peptides were discovered from the venom gland of D. acutus, and most of which peptides exhibited Factor XIa (FXIa) inhibitory activity. One of those, DAKS1, exhibiting strongest inhibitory activity against FXIa, was further evaluated for its anticoagulant and antithrombotic activity. DAKS1 prolonged twofold APTT at a concentration of 15 μM in vitro. DAKS1 potently inhibited thrombosis in a ferric chloride-induced carotid-artery injury model in mice at a dose of 1.3 mg/kg. Furthermore, DAKS1 prevented stroke in a transient middle cerebral-artery occlusion (tMCAO) model in mice at a dose of 2.6 mg/kg. Additionally, DAKS1 did not show significant bleeding risk at a dose of 6.5 mg/kg. Together, our results indicated that DAKS1 is a promising candidate for drug development for the treatment of thrombosis and stroke disorders.

scholarly journals Invitro Antidiabetic Activities of Agar, Agarosa, and Agaropectin from Gracilaria gigas Seaweed

2015 ◽  
Vol 18 (2) ◽  
Author(s):  
H. Hardoko ◽  
Agnes Febriani ◽  
Titri Siratantri
Keyword(s):  
Enzyme Activity ◽  
Inhibitory Activity ◽  
Ethanol Solution ◽  
Red Seaweed ◽  
Sulfate Content ◽  
Extract Agar ◽  
Ic50 Value ◽  
Extract Fraction

<p>Some types of seaweed are reported to have antidiabet activity in vivo or in vitro,<br />but the activity antidiabet fractions of polysaccharides from seaweed has not been widely<br />reported. Gracilaria gigas is one type of red seaweed that can produce agar and it has two<br />factions, namely agarose and agaropectin. The aim of this study was to obtain an agar<br />extract, agarose fraction, agaropektin fraction of Gracilaria gigas and to determine the<br />α-glucosidase inhibitory activity of extracts and the fractions. Extraction of agar that used<br />an ethanol solution, and to fractionate agarose and agaropektin used dimetilsulfoxide<br />solution. The results showed that the fraction of the agarose having lower sulfate content<br />(0.28%) compared with agar (5.91%) and agaropektin (6.07%). Types of samples (agar,<br />agarose, and agaropektin) and sample doses significantly in inhibiting α-glucosidase<br />enzyme activity. Agarose fraction has IC50 value against α-glucosidase lowest (96.86 ± 4.61<br />ppm), followed by the extract agar (116.63 ± 5.61 ppm), then the fraction agaropektin<br />(158.34 ± 1.77 ppm).<br />Keywords: α-glucosidase, extract, fraction, Gracilaria gigas, IC50</p>

scholarly journals EFFECT OF TRIGONELLA FOENUM GRAECUM ON ΑLPHA-GLUCOSIDASE AND DIPEPTIDYL PEPTIDASE-IV INHIBITORY ACTIVITY - AN IN VITRO STUDY

2018 ◽  
Vol 11 (10) ◽  
pp. 513
Author(s):  
Inbaraj Sd ◽  
Muniappan M
Keyword(s):  
Inhibitory Activity ◽  
Dipeptidyl Peptidase ◽  
Seed Extract ◽  
Inhibition Assay ◽  
Dipeptidyl Peptidase 4 ◽  
Trigonella Foenum Graecum ◽  
Ic50 Value ◽  
Alpha Glucosidase

Objective: The objective of this study is to find the effect of seed extract of Trigonella foenum graecum on the inhibition of α-glucosidase and dipeptidyl peptidase-4 (DPP-4) enzyme activity by in vitro method.Methods: Methanolic seed extract of T. foenum graecum seed was prepared and supplied by Sami Labs, Bengaluru, on request. For alpha-glucosidase inhibition assay, the following concentrations (0, 20, 40, 60, 80, and 100 μg/ml) of extracts and for DPP-4 inhibition assay (0, 5, 10, 20, 40, 80, 160, and 320d μg/ml) concentrations were used. The absorbance was measured at 540 and 405 nm using multiplate reader, and the percentage of α-glucosidase and DPP-4 enzyme inhibitory activity of extract fractions was calculated. Acarbose for alpha-glucosidase inhibition and vildagliptin for DDP-4 inhibition were used as standard drugs. The IC50 value for alpha-glucosidase inhibition and DPP-4 inhibition was determined.Results: The maximum alpha-glucosidase inhibitory activity of T. foenum graecum extract at 100 μg/ml was 68% (p<0.05) with IC50 value of 57.25 when compared to the acarbose (STD) of 94% with IC50 values of 42.78. The maximum percentage of DPP-4 inhibition of T. foenum graecum extract at 320 μg/ml is 77.84% (p<0.01) with IC50 value of 52.26 when compared to the vildagliptin (STD) it is 80.15% with IC50 value of 22.98.Conclusion: The results of the in vitro studies show that T. foenum graecum seed extract has significant alpha-glucosidase and DPP-4 inhibition. Further in vivo and clinical studies are necessary to establish the antihyperglycemic and antidiabetic potential of T. foenum graecum seed extract for the treatment of Type 2 diabetes mellitus.

The Effects of Some Synthetic Compounds on In Vitro Fibrinolytic Activity Measured by Different Methods and the Relevance to Activity In Vivo

1972 ◽  
Vol 28 (03) ◽  
pp. 351-358
Author(s):  
A.J Baillie ◽  
A. K Sim
Keyword(s):  
Inhibitory Activity ◽  
Substrate Concentration ◽  
Fibrinolytic Activity ◽  
Synthetic Compounds ◽  
In Vitro Methods ◽  
Narrow Concentration Range

SummaryThe activity of several synthetic compounds, rated from good to poor (or inactive) fibrinolytic activators, has been assessed by two different commonly-used in vitro methods. Compounds shown to be active over a narrow concentration range in the hanging clot test were shown to be inhibitors of plasmin and trypsin in the casein-olytic test. The inhibitory activity of these compounds was shown to increase with increasing substrate concentration and apparent activity in the hanging clot test. Possible explanations and relevance of these observations are discussed.

scholarly journals Potential In Vitro Inhibition of Selected Plant Extracts against SARS-CoV-2 Chymotripsin-Like Protease (3CLPro) Activity

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1503
Author(s):  
Carla Guijarro-Real ◽  
Mariola Plazas ◽  
Adrián Rodríguez-Burruezo ◽  
Jaime Prohens ◽  
Ana Fita
Keyword(s):  
Plant Extracts ◽  
Curcuma Longa ◽  
Hydrolysis Product ◽  
Resonance Energy ◽  
Significant Inhibition ◽  
Main Role ◽  
Turmeric Extract ◽  
Ic50 Value

Antiviral treatments inhibiting Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication may represent a strategy complementary to vaccination to fight the ongoing Coronavirus disease 19 (COVID-19) pandemic. Molecules or extracts inhibiting the SARS-CoV-2 chymotripsin-like protease (3CLPro) could contribute to reducing or suppressing SARS-CoV-2 replication. Using a targeted approach, we identified 17 plant products that are included in current and traditional cuisines as promising inhibitors of SARS-CoV-2 3CLPro activity. Methanolic extracts were evaluated in vitro for inhibition of SARS-CoV-2 3CLPro activity using a quenched fluorescence resonance energy transfer (FRET) assay. Extracts from turmeric (Curcuma longa) rhizomes, mustard (Brassica nigra) seeds, and wall rocket (Diplotaxis erucoides subsp. erucoides) at 500 µg mL−1 displayed significant inhibition of the 3CLPro activity, resulting in residual protease activities of 0.0%, 9.4%, and 14.9%, respectively. Using different extract concentrations, an IC50 value of 15.74 µg mL−1 was calculated for turmeric extract. Commercial curcumin inhibited the 3CLPro activity, but did not fully account for the inhibitory effect of turmeric rhizomes extracts, suggesting that other components of the turmeric extract must also play a main role in inhibiting the 3CLPro activity. Sinigrin, a major glucosinolate present in mustard seeds and wall rocket, did not have relevant 3CLPro inhibitory activity; however, its hydrolysis product allyl isothiocyanate had an IC50 value of 41.43 µg mL−1. The current study identifies plant extracts and molecules that can be of interest in the search for treatments against COVID-19, acting as a basis for future chemical, in vivo, and clinical trials.

scholarly journals Novel Role for Albumin in Innate Immunity: Serum Albumin Inhibits the Growth of Blastomyces dermatitidis Yeast Form In Vitro

2003 ◽  
Vol 71 (11) ◽  
pp. 6648-6652 ◽  
Author(s):  
Steven Giles ◽  
Charles Czuprynski
Keyword(s):  
Molecular Weight ◽  
Inhibitory Activity ◽  
Mammalian Species ◽  
Blastomyces Dermatitidis ◽  
Low Molecular Weight ◽  
Rat Serum ◽  
Yeast Form ◽  
Domain Iii

ABSTRACT In this study we found that serum inhibitory activity against Blastomyces dermatitidis was principally mediated by albumin. This was confirmed in experiments using albumin from several mammalian species. Analbuminemic rat serum did not inhibit B. dermatitidis growth in vivo; however, the addition of albumin restored inhibitory activity. Inhibitory activity does not require albumin domain III and appears to involve binding of a low-molecular-weight yeast-derived growth factor.

scholarly journals Andrographis paniculata (Burm. F.) Wall. Ex Nees, Andrographolide, and Andrographolide Analogues as SARS-CoV-2 Antivirals? A Rapid Review

2021 ◽  
Vol 16 (5) ◽  
pp. 1934578X2110166
Author(s):  
Xin Yi Lim ◽  
Janice Sue Wen Chan ◽  
Terence Yew Chin Tan ◽  
Bee Ping Teh ◽  
Mohd Ridzuan Mohd Abd Razak ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
In Silico ◽  
Rna Binding ◽  
Symptomatic Relief ◽  
Andrographis Paniculata ◽  
Spike Protein ◽  
Rapid Review ◽  
In Silico Studies

Drug repurposing is commonly employed in the search for potential therapeutic agents. Andrographis paniculata, a medicinal plant commonly used for symptomatic relief of the common cold, and its phytoconstituent andrographolide, have been repeatedly identified as potential antivirals against SARS-CoV-2. In light of new evidence emerging since the onset of the COVID-19 pandemic, this rapid review was conducted to identify and evaluate the current SARS-CoV-2 antiviral evidence for A. paniculata, andrographolide, and andrographolide analogs. A systematic search and screen strategy of electronic databases and gray literature was undertaken to identify relevant primary articles. One target-based in vitro study reported the 3CLpro inhibitory activity of andrographolide as being no better than disulfiram. Another Vero cell-based study reported potential SARS-CoV-2 inhibitory activity for both andrographolide and A. paniculata extract. Eleven in silico studies predicted the binding of andrographolide and its analogs to several key antiviral targets of SARS-CoV-2 including the spike protein-ACE-2 receptor complex, spike protein, ACE-2 receptor, RdRp, 3CLpro, PLpro, and N-protein RNA-binding domain. In conclusion, in silico and in vitro studies collectively suggest multi-pathway targeting SARS-CoV-2 antiviral properties of andrographolide and its analogs, but in vivo data are needed to support these predictions.

scholarly journals Monoclonal antibodies specific to a Ca2+-bound form of lipocortin I distinguish its Ca2+-dependent phospholipid-binding ability from its ability to inhibit phospholipase A2

1990 ◽  
Vol 269 (3) ◽  
pp. 709-715 ◽  
Author(s):  
H Hayashi ◽  
M K Owada ◽  
S Sonobe ◽  
K Domae ◽  
T Yamanouchi ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Phospholipase A2 ◽  
Inhibitory Activity ◽  
Biological Effects ◽  
Free Form ◽  
E Coli ◽  
Phospholipid Binding ◽  
Ef Hand

Lipocortin I, a Ca2(+)-and phospholipid-binding protein without EF-hand structures, has many biological effects in vitro. Its actual role in vivo, however is unknown. We obtained and characterized five monoclonal antibodies to lipocortin I. Two of these monoclonal antibodies (L2 and L4-MAbs) reacted with the Ca(+)-bound form of lipocortin I, but not with the Ca2(+)-free form, both in vivo and in vitro. Lipocortin I required greater than or equal to 10 microM-Ca2+ to bind the two antibodies, and this Ca2+ requirement was not affected by phosphatidylserine. L2-MAb abolished the phospholipase A2 inhibitory activity of lipocortin I and inhibited its binding to Escherichia coli membranes and to phosphatidylserine in vitro. L4-MAb abolished the phospholipase A2 inhibitory activity of lipocortin I, but did not affect its binding to E. coli membranes or to phosphatidylserine. These findings indicated that the inhibition of phospholipase A2 by lipocortin I was not simply due to removal or capping of the substrates in E. coli membranes. Furthermore, an immunofluorescence study using L2-MAb showed the actual existence of Ca2(+)-bound form of lipocortin I in vivo.

In-vitro and in vivo studies of traditionally prepared Zingiber officinale juice for Antimitotic and Lethality activity

2021 ◽  
pp. 4652-4656
Author(s):  
Nadar Sowmya ◽  
Chouhan Raghavendra Singh ◽  
Kosha Patel ◽  
Harshil Patel ◽  
Tanvi Dodiya ◽  
...  
Keyword(s):  
Zingiber Officinale ◽  
In Vivo Studies ◽  
Root Tip ◽  
Inhibition Assay ◽  
Lc50 Value ◽  
Antimitotic Activity ◽  
Ic50 Value ◽  
Traditionally Prepared

According to the literature survey most of the studies done on Adarak (Zingiber officinale rhizome) were performed on alcoholic extracts or isolated entities of ginger but no profound work has been done on the traditionally prepared or commonly consumed way of ginger. So, in this current study, fresh ginger rhizomes were traditionally pounded to make Adarak juice. The different concentration (0.05%, 0.5%, 1%, 2.5%, 5%, 10%) were taken as sample to perform onion root tip inhibition assay and brine shrimp lethality bioassay. It showed antimitotic inhibition in the range of 0.05-10% concentration with an IC50 value of 0.37 % on number of rootlets was 0.08 % on length of rootlets. The traditionally prepared Adarak juice showed cytotoxicity in the range of 0.05-2.5% concentration with LC50 value of 1.59%. The traditionally prepared Adarak juice possesses cytotoxic and antimitotic activity.

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