A1 Refereed original research article in a scientific journal
Interaction of cholera toxin B-subunit with human T-lymphocytes
Authors: Navolotskaya EV, Sadovnikov VB, Zinchenko DV, Zolotarev YA, Lipkin VM, Zav'yalov VP
Publisher: MAIK NAUKA/INTERPERIODICA/SPRINGER
Publication year: 2017
Journal: Биохимия / Biochemistry
Journal name in source: BIOCHEMISTRY-MOSCOW
Journal acronym: BIOCHEMISTRY-MOSCOW+
Volume: 82
Issue: 9
First page : 1036
Last page: 1041
Number of pages: 6
ISSN: 0006-2979
eISSN: 1608-3040
DOI: https://doi.org/10.1134/S0006297917090061
Abstract
In this work, I-125-labeled cholera toxin B-subunit (CT-B) (specific activity 98 Ci/mmol) was prepared, and its high-affinity binding to human blood T-lymphocytes (K (d) = 3.3 nM) was determined. The binding of the I-125-labeled CT-B was inhibited by unlabeled interferon-alpha(2) (IFN-alpha(2)), thymosin-alpha 1 (TM-alpha(1)), and by the synthetic peptide LKEKK, which corresponds to sequences 16-20 of human TM-alpha(1) and 131-135 of IFN-alpha(2) (K (i) 0.8, 1.2, and 1.6 nM, respectively), but was not inhibited by the unlabeled synthetic peptide KKEKL with inverted sequence (K (i) > 1 mu M). In the concentration range of 10-1000 nM, both CT-B and peptide LKEKK dose-dependently increased the activity of soluble guanylate cyclase (sGC) but did not affect the activity of membrane-bound guanylate cyclase. The KKEKL peptide tested in parallel did not affect sGC activity. Thus, the CT-B and peptide LKEKK binding to a common receptor on the surface of T-lymphocytes leads to an increase in sGC activity.
In this work, I-125-labeled cholera toxin B-subunit (CT-B) (specific activity 98 Ci/mmol) was prepared, and its high-affinity binding to human blood T-lymphocytes (K (d) = 3.3 nM) was determined. The binding of the I-125-labeled CT-B was inhibited by unlabeled interferon-alpha(2) (IFN-alpha(2)), thymosin-alpha 1 (TM-alpha(1)), and by the synthetic peptide LKEKK, which corresponds to sequences 16-20 of human TM-alpha(1) and 131-135 of IFN-alpha(2) (K (i) 0.8, 1.2, and 1.6 nM, respectively), but was not inhibited by the unlabeled synthetic peptide KKEKL with inverted sequence (K (i) > 1 mu M). In the concentration range of 10-1000 nM, both CT-B and peptide LKEKK dose-dependently increased the activity of soluble guanylate cyclase (sGC) but did not affect the activity of membrane-bound guanylate cyclase. The KKEKL peptide tested in parallel did not affect sGC activity. Thus, the CT-B and peptide LKEKK binding to a common receptor on the surface of T-lymphocytes leads to an increase in sGC activity.
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