Problems or Pitfalls

There are numerous difficulties with any type of chromatography. Perhaps the foremost is the expectation from a method containing the word 'specific' that one will obtain a highly purified material in a single chromatographic step. Occasionally this can be true, but far more commonly either lectin or boronate chromatography is just one of several steps needed to obtain a reasonably pure product. The true advantage of these two chromatographic methods, however, is that they complement standard chromatographic methods such as ion exchange, gel permeation and hydropho-bic chromatography.

Among the other problems associated with boron-ate and affinity chromatography is that the binding of molecules to a particular lectin or boronate can only be determined by trial and error. This calls for a fairly large pilot study which employs various lectins and/or boronate derivatives bound to various matrices and at several ligand concentrations. Without this information, it is difficult to optimize the separation; nevertheless, simple separations are sometimes done by taking a commercial immobilized lectin off the shelf and attempting a full chro-matographic separation. In most cases, this is done with a concanavilin A stationary phase, since Con A is relatively inexpensive, fairly stable, and has a broad specificity for a number of saccharide moieties. Thus it has a high probability of effecting a reasonable separation of glycated molecules from nonglycated molecules or from molecules which are glycated in significantly different ways. Con A has a primary binding to glucose or mannose moieties which are, fortunately, very common terminal sugars in glycated proteins.

An additional problem found in affinity chromatography is nonspecific binding. Both the lectin itself and the alkyl portion of the boronate can be the source of nonspecific binding.

One final problem with lectin chromatography is the high toxicity of some lectins. The reader should be warned that some lectins are highly toxic and must be handled with extreme caution, although others have little or no toxicity.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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