The effect of S‐100a and S‐100b proteins and Zn<sup>2+</sup> on the assembly of brain microtubule proteins in vitro

Deinum, Johanna; Baudier, Jacques; Briving, Carin; Rosengren, Lars; Wallin, Margareta; Gérard, Dominique; Haglid, Kenneth G.

doi:10.1016/0014-5793(83)80837-0

Cited by 22 publications

(4 citation statements)

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“…port such a hypothesis, a Ca2+and Zn2+-dependent inhibition of polymerization in v i m of the cytoskeleton protein tubulin by S lOOb protein (Baudier et d . , 1982b;Deinum et al, 1983) has been reported recently which may be related to the function of this protein in the brain.…”

Section: Discussionmentioning

confidence: 87%

Rat Brain S100b Protein: Purification, Characterization, and Ion Binding Properties. A Comparison with Bovine S100b Protein

Baudier

Labourdette

Gérard

1985

Journal of Neurochemistry

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We purified to homogeneity rat brain S100b protein, which constitutes about 90% of the soluble S100 protein fraction. Purified rat S100b protein comigrates with bovine S100b protein in nondenaturant system electrophoresis but differs in its amino acid composition and in its electrophoretic mobility in urea-sodium dodecyl sulfate-polyacrylamide gel with bovine S100b protein. The properties of the Ca2+ and Zn2+ binding sites on rat S100b protein were investigated by flow dialysis and by fluorometric titration, and the conformation of rat S100b in its metal-free form as well as in the presence of Ca2+ or Zn2+ was studied. The results were compared with those obtained for the bovine S100b protein. In the absence of KCl, rat brain S100b protein is characterized by two high-affinity Ca2+ binding sites with a KD of 2 X 10(-5) M and four lower affinity sites with KD about 10(-4) M. The calcium binding properties of rat S100b protein differ from bovine S100b only by the number of low-affinity calcium binding sites whereas similar Ca2+-induced conformational changes were observed for both proteins. In the presence of 120 mM KCl rat brain S100b protein bound two Zn2+-ions/mol of protein with a KD of 10(-7) M and four other with lower affinity (KD approximately equal to 10(-6) M). The occupancy of the two high-affinity Zn2+ binding sites was responsible for most of the Zn2+-induced conformational changes in the rat S100b protein. No increase in the tyrosine fluorescence quantum yield after Zn2+ binding to rat S100b was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Discussionmentioning

confidence: 87%

Rat Brain S100b Protein: Purification, Characterization, and Ion Binding Properties. A Comparison with Bovine S100b Protein

Baudier

Labourdette

Gérard

1985

Journal of Neurochemistry

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“…Effect of Calcium and Zinc on the Cross-Linking Reaction between SlOOb and the Microtubule-Associated r Protein. It was reported that SlOOb protein induced total disassembly of microtubules in vitro in a Ca2+-and Zn2+-dependent manner (Baudier et al, 1982b;Deinum et al, 1983;Donato et al, 1985) and that SI00 protein regulated microtubule assembly and stability in rat brain extracts (Hesketh & Baudier, 1986).…”

Section: Resultsmentioning

confidence: 99%

Reinvestigation of the sulfhydryl reactivity in bovine brain S100b (.beta..beta.) protein and the microtubule-associated .tau. proteins. Calcium stimulates disulfide cross-linking between S100b .beta.-subunit and the microtubule-associated .tau.(2) protein

Baudier¹,

Cole²

1988

Biochemistry

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Zn2+ and Ca2+ affect the conformation of bovine brain S100b (beta beta) protein and the exposure of its Cys-84 beta. Zn2+ binding to high-affinity sites of native S100b protected the sulfhydryl groups against the thiol-specific reagent 5,5'-dithiobis(2-nitrobenzoate) and antagonized the Ca2+-stimulated reactivity of Cys-84 beta toward the reagent. Spectroscopic studies on the fluorescence properties of labeled S100b with the fluorescent probes bimane and acrylodan at Cys-84 beta confirmed the antagonistic effect of Ca2+ and Zn2+ with respect to the conformational properties of the protein. Measurements of fluorescence dynamics on bimane-labeled S100b indicated that the slow monomer-dimer equilibrium that characterizes the apoprotein at micromolar concentrations was shifted to the monomer form in the presence of Zn2+, a fact that could explain the previously reported Zn2+-dependent increase of S100b protein affinity for calcium. The difference in the effects of Ca2+ and Zn2+ on the reactivity of Cys-84 beta in S100b was confirmed when we observed that Ca2+ and Zn2+ have opposite actions on the formation of disulfide bridges between Cys-84 beta of the S100b beta-subunit and sulfhydryl groups on the microtubule-associated tau(2) protein. Ca2+ stimulated the covalent complex formation whereas Zn2+ inhibited it. We suggest that Zn2+ may have a modulatory function on Cys-84 beta reactivity in the S100b beta-subunit in vivo. Two types of divalent complexes between tau(2) and beta-subunit were formed in the presence of Ca2+, an equimolar complex tau(2)-beta 1 and a complex of one molecule of tau(2) with two beta-subunits, tau(2)-beta 2.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…By contrast, in the case of tubulin, the constant is significantly lower (K D ~10 -5 M), which means that S100A1 could act as a Zn 2+ acceptor rather than a donor when forming a complex with tubulin [56,59]. This suggestion is supported by the stabilizing effect of S100A1 on microtubules in the presence of Zn 2+ , which otherwise induces their disassembly [60].…”

Section: Discussionmentioning

confidence: 99%

Mechanism of Zn2+ and Ca2+ Binding to Human S100A1

et al. 2021

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S100A1 is a member of the S100 family of small ubiquitous Ca2+-binding proteins, which participates in the regulation of cell differentiation, motility, and survival. It exists as homo- or heterodimers. S100A1 has also been shown to bind Zn2+, but the molecular mechanisms of this binding are not yet known. In this work, using ESI-MS and ITC, we demonstrate that S100A1 can coordinate 4 zinc ions per monomer, with two high affinity (KD~4 and 770 nm) and two low affinity sites. Using competitive binding experiments between Ca2+ and Zn2+ and QM/MM molecular modeling we conclude that Zn2+ high affinity sites are located in the EF-hand motifs of S100A1. In addition, two lower affinity sites can bind Zn2+ even when the EF-hands are saturated by Ca2+, resulting in a 2Ca2+:S100A1:2Zn2+ conformer. Finally, we show that, in contrast to calcium, an excess of Zn2+ produces a destabilizing effect on S100A1 structure and leads to its aggregation. We also determined a higher affinity to Ca2+ (KD~0.16 and 24 μm) than was previously reported for S100A1, which would allow this protein to function as a Ca2+/Zn2+-sensor both inside and outside cells, participating in diverse signaling pathways under normal and pathological conditions.

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The effect of S‐100a and S‐100b proteins and Zn²⁺ on the assembly of brain microtubule proteins in vitro

Cited by 22 publications

References 20 publications

Rat Brain S100b Protein: Purification, Characterization, and Ion Binding Properties. A Comparison with Bovine S100b Protein

Rat Brain S100b Protein: Purification, Characterization, and Ion Binding Properties. A Comparison with Bovine S100b Protein

Reinvestigation of the sulfhydryl reactivity in bovine brain S100b (.beta..beta.) protein and the microtubule-associated .tau. proteins. Calcium stimulates disulfide cross-linking between S100b .beta.-subunit and the microtubule-associated .tau.(2) protein

Mechanism of Zn2+ and Ca2+ Binding to Human S100A1

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The effect of S‐100a and S‐100b proteins and Zn2+ on the assembly of brain microtubule proteins in vitro

Cited by 22 publications

References 20 publications

Rat Brain S100b Protein: Purification, Characterization, and Ion Binding Properties. A Comparison with Bovine S100b Protein

Rat Brain S100b Protein: Purification, Characterization, and Ion Binding Properties. A Comparison with Bovine S100b Protein

Reinvestigation of the sulfhydryl reactivity in bovine brain S100b (.beta..beta.) protein and the microtubule-associated .tau. proteins. Calcium stimulates disulfide cross-linking between S100b .beta.-subunit and the microtubule-associated .tau.(2) protein

Mechanism of Zn2+ and Ca2+ Binding to Human S100A1

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The effect of S‐100a and S‐100b proteins and Zn²⁺ on the assembly of brain microtubule proteins in vitro