{"title":"Zinc binding of a Cys2His2-type zinc finger protein is enhanced by the interaction with DNA","authors":"Bálint Hajdu, Éva Hunyadi-Gulyás, Kohsuke Kato, Atsushi Kawaguchi, Kyosuke Nagata, Béla Gyurcsik","doi":"10.1007/s00775-023-01988-1","DOIUrl":null,"url":null,"abstract":"<p>Zinc finger proteins specifically recognize DNA sequences and, therefore, play a crucial role in living organisms. In this study the Zn(II)-, and DNA-binding of 1MEY#, an artificial zinc finger protein consisting of three finger units was characterized by multiple methods. Fluorimetric, circular dichroism and isothermal calorimetric titrations were applied to determine the accurate stability constant of a zinc finger protein. Assuming that all three zinc finger subunits behave identically, the obtained thermodynamic data for the Zn(II) binding were <i>ΔH</i><sub>binding site</sub> = − (23.5 − 28.0) kcal/mol (depending on the applied protonation state of the cysteines) and log<i>β</i>’<sub>pH 7.4</sub> = 12.2 ± 0.1, being similar to those of the CP1 consensus zinc finger peptide. The specific DNA binding of the protein can be characterized by log<i>β</i>’<sub>pH 7.4</sub> = 8.20 ± 0.08, which is comparable to the affinity of the natural zinc finger proteins (Sp1, WT1, TFIIIA) toward DNA. This value is ~ 1.9 log<i>β</i>’ unit higher than those determined for semi- or nonspecific DNA binding. Competitive circular dichroism and electrophoretic mobility shift measurements revealed that the conditional stability constant characteristic for Zn(II) binding of 1MEY# protein increased by 3.4 orders of magnitude in the presence of its target DNA sequence.</p>","PeriodicalId":603,"journal":{"name":"JBIC Journal of Biological Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2023-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00775-023-01988-1.pdf","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"JBIC Journal of Biological Inorganic Chemistry","FirstCategoryId":"1","ListUrlMain":"https://link.springer.com/article/10.1007/s00775-023-01988-1","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 1
Abstract
Zinc finger proteins specifically recognize DNA sequences and, therefore, play a crucial role in living organisms. In this study the Zn(II)-, and DNA-binding of 1MEY#, an artificial zinc finger protein consisting of three finger units was characterized by multiple methods. Fluorimetric, circular dichroism and isothermal calorimetric titrations were applied to determine the accurate stability constant of a zinc finger protein. Assuming that all three zinc finger subunits behave identically, the obtained thermodynamic data for the Zn(II) binding were ΔHbinding site = − (23.5 − 28.0) kcal/mol (depending on the applied protonation state of the cysteines) and logβ’pH 7.4 = 12.2 ± 0.1, being similar to those of the CP1 consensus zinc finger peptide. The specific DNA binding of the protein can be characterized by logβ’pH 7.4 = 8.20 ± 0.08, which is comparable to the affinity of the natural zinc finger proteins (Sp1, WT1, TFIIIA) toward DNA. This value is ~ 1.9 logβ’ unit higher than those determined for semi- or nonspecific DNA binding. Competitive circular dichroism and electrophoretic mobility shift measurements revealed that the conditional stability constant characteristic for Zn(II) binding of 1MEY# protein increased by 3.4 orders of magnitude in the presence of its target DNA sequence.
期刊介绍:
Biological inorganic chemistry is a growing field of science that embraces the principles of biology and inorganic chemistry and impacts other fields ranging from medicine to the environment. JBIC (Journal of Biological Inorganic Chemistry) seeks to promote this field internationally. The Journal is primarily concerned with advances in understanding the role of metal ions within a biological matrix—be it a protein, DNA/RNA, or a cell, as well as appropriate model studies. Manuscripts describing high-quality original research on the above topics in English are invited for submission to this Journal. The Journal publishes original articles, minireviews, and commentaries on debated issues.