Arginine separation from other amino acids

Can we utilize this pH-dependent ionization of amino acids for their separation A small example will answer the question. We are given a mixture of three amino acids, alanine, aspartic acid, and arginine. It is required that we separate these three amino acids from each other and obtain them in a more or less pure state. From Table 1.8 we can find out that the pi of alanine. 

Most of the work in this field has been carried out in Butler s laboratory (Johns et al., 1960, 1961 Hnilica et al, 1962 Johns and Butler, 1962). As a result of their investigations, histone from thymus desoxyribonucleoprotein (DNP) was first separated by electrophoresis on starch into three fractions arginine (f3), lysine-rich (fj), and a fraction with a lower lysine content (f2). In fraction f3, alanine usually occupied the terminal position. Histones of the f2 group were separated by electrophoresis on starch into subfractions f2a and f2b, differing in their N-terminal groups. The lysine-rich fraction also was separated into la and fib> likewise differing in their N-terminal amino acids. Distinct differences between these fractions were also found for other amino acids. 

A mixture of alanine, glutamic acid, and arginine was chromatographed on a weakly basic ion-exchange column (positively charged) at pH 6.1. Predict the order of elution of the amino acids from the ion-exchange column. Are the amino acids separated from each other Explain. 

Many separation system possibilities exist, with one provided in Figure 3.14. Here, the reactor effluent is sent to a separator for recovery of the gas emissions from the liquid mixture, with the latter sent to a centrifuge to remove wet cell debris from the harvest media or clarified broth. Note that because proteins lose their activity at temperatures above 0 C, the centrifuge, and all other separation operations, are operated at 4°C, slightly above the freezing point of water. The harvest media is mixed with arginine hydrochloride, an amino acid ... 

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