Diaminodiacid bridge improves enzymatic and in vivo inhibitory activity of peptide CPI-1 against botulinum toxin serotype A

Author(s):  
Jintao Shen ◽  
Jia Liu ◽  
Shuo Yu ◽  
Yunzhou Yu ◽  
Chao Huang ◽  
...  
2020 ◽  
Vol 133 (2) ◽  
pp. 588-595
Author(s):  
Davis P. Argersinger ◽  
Stuart Walbridge ◽  
Nicholas M. Wetjen ◽  
Alexander O. Vortmeyer ◽  
Tianxia Wu ◽  
...  

OBJECTIVEBotulinum toxin serotype A (BoNT/A) was reported to raise the seizure threshold when injected into the seizure focus of a kindled rodent model. Delivering BoNT/A to the nonhuman primate (NHP) central nervous system via convection-enhanced delivery (CED) has not been performed. The objective of this study was to determine the toxicity and distribution characteristics of CED of BoNT/A into the NHP hippocampus and cisterna magna.METHODSEscalating BoNT/A doses were delivered by CED into the NHP hippocampus (n = 4) and cisterna magna (n = 5) for behavioral and histological assessment and to determine the highest nonlethal dose (LD0) and median lethal dose (LD50). Hippocampal BoNT/A was coinfused with Gd-albumin, a surrogate MRI tracer. Gd-albumin and radioiodinated BoNT/A (125I-BoNT/A) were coinfused into the hippocampus of 3 additional NHPs to determine BoNT/A distribution by in vivo MRI and postmortem quantitative autoradiography. Scintillation counting of CSF assessed the flow of 125I-BoNT/A from the hippocampus to CSF postinfusion.RESULTSLD0 and LD50 were 4.2 and 18 ng/kg, and 5 and > 5 ng/kg for the NHP hippocampus and cisterna magna, respectively. Gd-albumin and 125I-BoNT/A completely perfused the hippocampus (155–234 mm3) in 4 of 7 NHPs. Fifteen percent of BoNT/A entered CSF after hippocampal infusion. The MRI distribution volume of coinfused Gd-albumin (VdMRI) was similar to the quantitative autoradiography distribution of 125I-BoNT/A (VdQAR) (mean VdMRI = 139.5 mm3 [n = 7]; VdQAR = 134.8 mm3 [n = 3]; r = 1.00, p < 0.0001). No infusion-related toxicity was identified histologically except that directly attributable to needle placement.CONCLUSIONSGd-albumin accurately tracked BoNT/A distribution on MRI. BoNT/A did not produce CNS toxicity. BoNT/A LD0 exceeded 10-fold the dose administered safely to humans for cosmesis and dystonia.


1972 ◽  
Vol 28 (03) ◽  
pp. 351-358
Author(s):  
A.J Baillie ◽  
A. K Sim

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.


2019 ◽  
Vol 16 (3) ◽  
pp. 175-180
Author(s):  
Fengjin Hao ◽  
Yueqin Feng ◽  
Yifu Guan

Objective: To verify whether the botulinum toxin heavy chain HCS has specific neuronal targeting function and to confirm whether TAT-EGFP-LC has hydrolyzable SNAP-25 and has transmembrane biological activity. Methods: We constructed the pET-28a-TAT-EGFP-HCS/LC plasmid. After the plasmid is expressed and purified, we co-cultured it with nerve cells or tumors. In addition, we used Western-Blot to identify whether protein LC and TAT-EGFP-LC can digest the protein SNAP-25. Results: Fluorescence imaging showed that PC12, BV2, C6 and HeLa cells all showed green fluorescence, and TAT-EGFP-HCS had the strongest fluorescence. Moreover, TAT-EGFP-LC can hydrolyze intracellular SNAP-25 in PC12 cells, C6 cells, BV2 cells and HeLa, whereas LC alone cannot. In addition, the in vivo protein TAT-EGFP-HCS can penetrate the blood-brain barrier and enter mouse brain tissue. Conclusion: TAT-EGFP-HSC expressed in vitro has neural guidance function and can carry large proteins across the cell membrane without influencing the biological activity.


2003 ◽  
Vol 71 (11) ◽  
pp. 6648-6652 ◽  
Author(s):  
Steven Giles ◽  
Charles Czuprynski

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.


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 ◽  
...  

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.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Saiful Azmi Johari ◽  
Mastura Mohtar ◽  
Sharifah Aminah Syed Mohammad ◽  
Rohana Sahdan ◽  
Zurina Shaameri ◽  
...  

28 new pyrrolidine types of compounds as analogues for natural polyhydroxy alkaloids of codonopsinine were evaluated for their anti-MRSA activity using MIC and MBC value determination assay against a panel ofS. aureusisolates. One pyrrolidine compound, MFM 501, exhibited good inhibitory activity with MIC value of 15.6 to 31.3 μg/mL against 55S. aureusisolates (43 MRSA and 12 MSSA isolates). The active compound also displayed MBC values between 250 and 500 μg/mL against 58S. aureusisolates (45 MRSA and 13 MSSA isolates) implying that MFM 501 has a bacteriostatic rather than bactericidal effect against both MRSA and MSSA isolates. In addition, MFM 501 showed no apparent cytotoxicity activity towards three normal cell lines (WRL-68, Vero, and 3T3) with IC50values of >625 µg/mL. Selectivity index (SI) of MFM 501 gave a value of >10 suggesting that MFM 501 is significant and suitable for furtherin vivoinvestigations. These results suggested that synthetically derived intermediate compounds based on natural products may play an important role in the discovery of new anti-infective agents against MRSA.


1990 ◽  
Vol 269 (3) ◽  
pp. 709-715 ◽  
Author(s):  
H Hayashi ◽  
M K Owada ◽  
S Sonobe ◽  
K Domae ◽  
T Yamanouchi ◽  
...  

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.


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