Starch block preparation

At the close of the dialysis the plasma was centrifuged to remove small amounts of precipitate and the clear plasma resulting was subjected to starch-block preparative zone electrophoresis by the technique of Kunkel and Slater (15). At the close of the electrophoresis 1-cm. segments of the starch block were cut and transferred to sintered glass funnels, and the proteins were quantitatively eluted with five successive 2-ml. aliquots of 0.9% sodium chloride. The filtrates containing the protein fractions were then made up to a constant volume and mixed, and small aliquots were analyzed for total protein content by the method of Lowry et al. (18). 

Besides starch block, electrophoresis has not seen wide use in the separation of plasma lipoproteins on a preparative scale. Since the applications of electrophoresis to the study of plasma lipoproteins have been dealt with in recent reviews (H2, L3, M4), they will not be discussed here. 

Starch was introduced by Kunkel and Slater (K3) and used for preparative work, as the starch block can be cut up according to fractions after separation of rather large quantities of serum. The separations are very sharp, but in practice the cutting up is difficult, as in some cases the zones are numerous and narrow and are often curved or jagged. Others studied lipoproteins (Bl) and lipids (Al) with an analogous technique. 

The best results in the starch block separation are achieved with 2 cc. or less of serum. However, fair separation can be obtained with a quantity up to 5 cc. Above this the band of origin becomes too broad and thicker blocks are necessary. In general, blocks more than 2 cm. in thickness have proved unsatisfactory, due in part to poorer dissipation of heat and increased gravity effects. Distortion of the bands with a marked curvature in the albumin component may be observed. The best results have been obtained with serum diluted with buffer to two-thirds concentration or less viscosity effects are prominent when whole serum is employed. The electroosmotic flow of water is only slightly greater than that observed with the usual filter papers. In a serum separation, most of the y-globulin falls behind the origin on the cathode side at pH 8.6. A wide application of the starch system for small-scale preparative electrophoresis, particularly of serum, has recently developed. Early observations indicated a... 

Luck and Durnford. Proposed, in 1896, to prepare proplnt powd from nitrated hydrocellulose which had been treated with aq starch soln. This allowed the material to be compacted into grains, blocks, leaflets, etc Ref Daniel (1902), 411-12. 

Naturally the implication arose that there should be a high incidence of common peptides in the partial hydrolyzates of each of the serum proteins. This, of course, is the same implication that arose in Block s mind (3). Since 1956 this laboratory has been busy trying to isolate common peptides from each of the serum proteins as obtained from electrophoresis on starch slabs. In order to be able to prepare each of the protein hydrolyzates simultaneously we examined nonenzy-matic procedures and devised the dilute acid partial hydrolyzate method which has recently been described in detail (33, 34). In this method aspartic acid is preferentially eliminated from the peptide chain, the re-... 

At present succinic acid is a specialty chemical with an annual production volume of about 30 000 tons worldwide. Fossil-based succinic acid is most commonly prepared via hydrogenation of maleic anhydride (by oxidation of n-butane or benzene) [73]. In the field of bio-based chemicals and building blocks succinic acid is considered to be one of the most important platform chemicals [1, 74, 75], and as a result of the introduction of biosuccinic acid the production volume is expected to double or triple within years. Several fermentation processes have been described to produce bio-based succinic acid. Common feedstocks for these processes include glucose, starch and xylose [76]. The commercial potential for bio-succinic acid is illustrated by the numerous initiatives by companies that are working towards, or already... 

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