Further purification of the microbubble surfactant mixture by gel-filtration column chromatography

3 Further purification of the microbubble surfactant mixture by gel-filtration column chromatography 

4 Amino acid composition of the main glvcopeptide subfraction from microbubble surfactant 

To obtain data on the heterogeneity of the glycopeptide fraction of microbubble surfactant, comparative amino acid analyses were performed on two of the major peaks obtained from gel filtration. From the ratio of absorbances at 230 and 280 nm (ref. 265) and the elution profile shown in Fig. 5.3, it appeared that peaks I and III would differ the most in amino acid composition and, therefore, these two peaks were selected for amino acid analysis. Peak I was sufficiently large to be divided into three equal aliquots and peak III into two equal aliquots for automated analysis. Peak II, which eluted closest (Fig. 5.3) to the dominant peak I and presumably was most similar in molecular composition to this large initial peak, was analyzed separately by HPLC for carbohydrate content. 

Amino acid composition3 of microbubble surfactant peaks obtained from Sephadex LH-20 chromatography (shown in Fig. 5.3). (Taken from ref. 356.) 

Amino acid Peak I determinations Peak III determinations  

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