JSFiddle - React, Tailwind, and code Playground

HTML

<select id="billing:region_id" name="billing[region_id]">
    <option value="">Por favor, selecione o estado</option>
    <option data-sigla="AC" value="485">Acre</option>
    <option data-sigla="AL" value="486">Alagoas</option>
    <option data-sigla="CE" value="490">Ceará</option>
    <option data-sigla="DF" value="511">Distrito Federal</option>
    <option data-sigla="ES" value="491">Espírito Santo</option>
</select>

JavaScript

var dados = {
    uf: 'DF'
};
var options = [].slice.call(document.querySelectorAll('option'));


function select(str) {
    options.forEach(function(option) {
        if (option.dataset.sigla == str) option.setAttribute('selected', 'selected');
        else option.removeAttribute('selected');
    });
}

select(dados.uf);