Lysinoalanine Determination in Proteins

Lysinoalanine in foods

“…Forms of thin-layer chromatography (TLC) have also been used (Woods and Wang, 1967;Sternberg et al, 1975a), and although the lower level of sensitivity is rather low (3 ng), it requires a long separation time (Haagsma and Gortemaker, 1979), and when compared to ion-exchange techniques, large standard deviations (Haagsma and Slump, 1978) make the widespread use of the technique somewhat limited. It should be noted that separation time has now been shortened to approximately 4 h (Aymard et al, 1978).…”

Determination of the Lysinoalanine Content in Commercial Foods by Gas Chromatography-selected Ion Monitoring

“…19) In the proteins of home-cooked and commercial foods, unusual amino acids other than primary protein amino acids are produced from the reaction of the proteins with other food components during processing, storage and cooking. Therefore, the determination of LAL by these chromatographic methods is liable to give erroneous results, since the peak or spot of these unusual and unidentified amino acids on these chromatograms may overlap with that of LAL.…”

Lysinoalanine in alkali-solubilized protein crystal toxin from Bacillus thuringiensis

“…Lysinoalanine was monitored in the native and alkali-solubilized crystals by the thin-layer chromatography procedure of Sternberg [ 11 ] as modified by Wu [12]. Fig.…”

“…Lysinoalanine has been detected following the alkaline treatment of several other proteins [ 15,16], and much attention has been given to both its potential toxicity [11] and its mode of formation [17,18]. The most common pathway for lysinoalanine formation [17] involves the alkaline E-elimination whereby cleavage of O-glycosyl linkages connecting the sugar portion of a glycoprotein to its Ser and Thr residues yields c~-i5 unsaturated amino acids such as dehydroalanine.…”