scholarly journals In Vitro Selection of Cathepsin E-Activity-Enhancing Peptide Aptamers at Neutral pH

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Madhu Biyani ◽  
Masae Futakami ◽  
Koichiro Kitamura ◽  
Tomoyo Kawakubo ◽  
Miho Suzuki ◽  
...  
Keyword(s):  
In Vitro Selection ◽  
Physiological Activity ◽  
Peptide Aptamers ◽  
Neutral Ph ◽  
Cathepsin E ◽  
Analysis System ◽  
Ph Range ◽  
Cancerous Cells ◽  
Inverse Substrate

The aspartic protease cathepsin E has been shown to induce apoptosis in cancer cells under physiological conditions. Therefore, cathepsin E-activity-enhancing peptides functioning in the physiological pH range are valuable potential cancer therapeutic candidates. Here, we have used a general in vitro selection method (evolutionary rapid panning analysis system (eRAPANSY)), based on inverse substrate-function link (SF-link) selection to successfully identify cathepsin E-activity-enhancing peptide aptamers at neutral pH. A successive enrichment of peptide activators was attained in the course of selection. One such peptide activated cathepsin E up to 260%, had a high affinity (KD; ∼300 nM), and had physiological activity as demonstrated by its apoptosis-inducing reaction in cancerous cells. This method is expected to be widely applicable for the identification of protease-activity-enhancing peptide aptamers.

In vitro selection of peptide aptamers using a ribosome display for a conducting polymer

2014 ◽  
Vol 117 (4) ◽  
pp. 501-503 ◽  
Author(s):  
Zha Li ◽  
Takanori Uzawa ◽  
Haichao Zhao ◽  
Shyh-Chyang Luo ◽  
Hsiao-hua Yu ◽  
...  
Keyword(s):  
Conducting Polymer ◽  
In Vitro Selection ◽  
Ribosome Display ◽  
Peptide Aptamers ◽  
Selection Of

Amino group binding peptide aptamers with double disulphide-bridged loops selected by in vitro selection using cDNA display

2014 ◽  
Vol 50 (42) ◽  
pp. 5608-5610 ◽  
Author(s):  
Yuki Mochizuki ◽  
Koichi Nishigaki ◽  
Naoto Nemoto
Keyword(s):  
In Vitro Selection ◽  
Amino Group ◽  
Peptide Aptamers ◽  
Binding Peptide ◽  
Peptide Aptamer

Double disulphide-bridged loops of peptide aptamer are indispensable for the amino group recognition.

In vitro selection of peptide aptamers with affinity to single-wall carbon nanotubes using a ribosome display

2012 ◽  
Vol 35 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Zha Li ◽  
Takanori Uzawa ◽  
Takashi Tanaka ◽  
Akira Hida ◽  
Koji Ishibashi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
In Vitro Selection ◽  
Single Wall Carbon Nanotubes ◽  
Ribosome Display ◽  
Peptide Aptamers ◽  
Single Wall Carbon ◽  
Selection Of

Reaction of Acetaldehyde with Human Platelets

1992 ◽  
Vol 67 (01) ◽  
pp. 126-130 ◽  
Author(s):  
Olivier Spertini ◽  
Jacques Hauert ◽  
Fedor Bachmann
Keyword(s):  
Platelet Aggregation ◽  
Inhibitory Action ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Shape Change ◽  
Reaction Medium ◽  
Human Platelets ◽  
Membrane Glycoproteins ◽  
Neutral Ph

SummaryPlatelet function defects observed in chronic alcoholics are not wholly explained by the inhibitory action of ethanol on platelet aggregation; they are not completely reproduced either in vivo by short-term ethanol perfusion into volunteers or in vitro by the addition of ethanol to platelet-rich plasma. As acetaldehyde (AcH) binds to many proteins and impairs cellular activities, we investigated the effect of this early degradation product of ethanol on platelets. AcH formed adducts with human platelets at neutral pH at 37° C which were stable to extensive washing, trichloracetic acid hydrolysis and heating at 100° C, and were not reduced by sodium borohydride. The amount of platelet adducts formed was a function of the incubation time and of the concentration of AcH in the reaction medium. At low AcH concentrations (<0.2 mM), platelet bound AcH was directly proportional to the concentration of AcH in the reaction medium. At higher concentrations (≥0.2 mM), AcH uptake by platelets tended to reach a plateau. The amount of adducts was also proportional to the number of exposures of platelets to pulses of 20 pM AcH.AcH adducts formation severely impaired platelet aggregation and shape change induced by ADP, collagen and thrombin. A positive correlation was established between platelet-bound AcH and inhibition of aggregation.SDS-PAGE analysis of AcH adducts at neutral pH demonstrated the binding of [14C]acetaldehyde to many platelet proteins. AcH adduct formation with membrane glycoproteins, cytoskeleton and enzymes might interfere with several steps of platelet activation and impair platelet aggregation.This in vitro study shows that AcH has a major inhibitory action on platelet aggregation and may account for the prolonged ex vivo inhibition of aggregation observed in chronic alcoholics even in the absence of alcoholemia.

STEROID HORMONE METABOLISM IN RESPONSIVE TISSUES IN VITRO

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S279-S294 ◽  
Author(s):  
Paul Robel
Keyword(s):  
Steroid Hormone ◽  
Physiological Activity ◽  
Physiological State ◽  
Target Cells ◽  
Target Tissue ◽  
Hormone Metabolism ◽  
Metabolizing Enzymes ◽  
Relationship Of

ABSTRACT Of the information available on steroid hormone metabolism in responsive tissues, only that relating hormone metabolism to physiological activity is reviewed, i. e. metabolite activity in isolated in vitro systems, binding of metabolites to target tissue receptors, specific steroid hormone metabolizing enzymes and relationship of hormone metabolism to target organ physiological state. Further, evidence is presented in the androgen field, demonstrating 5α-reduced metabolites, formed inside the target cells, as active compounds. This has led to a consideration of testosterone as a »prehormone«. The possibility that similar events take place in tissues responding to progesterone is discussed. Finally, the role of hormone metabolism in the regulation of hormone availability and/or renewal in target cells is discussed. In this context, reference is made to the potential role of plasma binding proteins and cytosol receptors.

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