{"id":6741,"date":"2006-10-11T20:26:39","date_gmt":"2006-10-11T20:26:39","guid":{"rendered":"https:\/\/www.gluon.com.br\/franca\/2006\/10\/11\/artigo1\/"},"modified":"2006-10-11T20:26:39","modified_gmt":"2006-10-11T20:26:39","slug":"artigo1","status":"publish","type":"post","link":"https:\/\/www.gluon.com.br\/blog\/2006\/10\/11\/artigo1\/","title":{"rendered":"Artigo 1 – Magnetic techniques for the isolation and purification of proteins and peptides"},"content":{"rendered":"


\nMagnetic techniques for the isolation and purification of proteins and peptides
\nIvo Safarik and Mirka Safarikova<\/strong>
\nDOI: doi:10.1186\/1477-044X-2-7<\/a><\/p>\n

<\/a>Questions<\/h3>\n
Column liquid chromatography<\/strong>superparamagnetic<\/strong>
\nSuperparamagnetism<\/a> is a phenomenon by which magnetic materials may exhibit a behavior similar to paramagnetism even when at temperatures below the Curie or the Neel temperature. This is observed in very fine particles, where the energy required to change the direction of the magnetic moment of a particle is comparable to the ambient thermal energy. At this point, the rate at which the particles will randomly reverse direction becomes significant.
\nmaghemite<\/strong>
\nMaghemite<\/a> (Fe2<\/sub>O3<\/sub>, \u03b3-Fe2<\/sub>O3<\/sub>) is a member of the family of iron oxide<\/a>s. It has the same structure as magnetite<\/a>, that is, it is spinel<\/a> Ferrite and is also ferrimagnetic<\/a>. Maghemite can be considered as an Fe(II)-deficient magnetite.
\nferrites<\/strong>
\nFerrites are electrically non-conductive ferrimagnetic ceramic compound materials, consisting of iron oxides such as Hematite (Fe2O3) or Magnetite (Fe3O4) plus other metal oxides. In saturated state they conduct a magnetic flux very well and have a high magnetic permeability, which allows them to store stronger magnetic fields than iron, and are known as ceramic magnets. (from wikipedia)agar<\/a>ose<\/strong>
\nAgar is a heterogeneous mixture of two classes of polysaccharide: agaropectin and agarose [1]. Although both polysaccharide classes share the same galactose-based backbone, agaropectin is heavily modified with acidic side-groups, such as sulfate and pyruvate. The neutral charge and lower degree of chemical complexity of agarose make it less likely to interact with biomolecules, such as proteins. Gels made from purified agarose have a relatively large pore size, making them useful for size-separation of large molecules, such as proteins or protein complexes >200 kilodaltons, or DNA fragments >100 basepairs. Agarose can be used for electrophoretic separation or for column-based gel filtration chromatography.
\nchitosan<\/a><\/strong>
\nChitosan is a linear polysaccharide composed of randomly distributed \u00df-(1-4)-linked D-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit).
\nkappa carrageenan<\/a><\/strong>
\nCarrageenans (pronounced [\u02cck\u00e6r\u0259\u02c8gi\u02d0n\u0259ns]) are a family of linear sulphated polysaccharides extracted from red seaweeds.
\nThere are three main commercial classes of carrageenan:<\/p>\n