Clues to the origin of high external invertase activity in immobilized growing yeast: prolongedSUC2transcription and less susceptibility of the enzyme to endogenous proteolysis

Abstract

Expression of the SUC2 gene encoding invertase was studied using free and gelatin-immobilized yeast cells to try to explain the high activity of this enzyme exhibited by immobilized cells when allowed to grow in a nutrient medium. The results indicated that at least two factors are probably responsible for the accumulation of invertase in immobilized cells. First, the expression of the SUC2 gene was maintained throughout growth in immobilized cells, whereas its expression was only transient in free cells. Second, invertase of immobilized cells was shown to be less susceptible to endogenous proteolytic attack than that of the corresponding free cells. These results have been interpreted, respectively, in terms of diffusional limitations and changes in the pattern of invertase glycosylation due to growth of yeast in an immobilized state.

Gelatin-immobilized metal complexes: synthesis and applications

“…The probability of template synthesis rises as mobility of the hydrogen atoms in the ligand synthon becomes greater. Gelatin molecules in alkaline medium have a negative charge [24][25][26][27]; therefore, proton-donating capability of the compounds immobilized in such gels are more pronounced than in aqueous solution. It thus follows that template synthesis in the metal hexacyanoferrate(II) gelatin-immobilized matrix should proceed more effectively than the same process in a solution or the solid phase .…”

“…Metal-containing immobilized materials of type (b) and chemical processes in them, including complexation reactions, however, have not received proper attention. It should be noted in this connection that gelatinimmobilized systems rather widely are employed in biochemistry (see, for example, [24][25][26][27][28][29][30][31][32][33]). …”