Clues to the origin of high external invertase activity in immobilized growing yeast: prolonged SUC2 transcription and less susceptibility of the enzyme to endogenous proteolysis.
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.
de Alteriis
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Dip. to Fisiologia Generale, Università degli Studi di Napoli, Italy.
Alepuz
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PM
Estruch
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Parascandola
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P
D003470:Culture Media / Q000737:chemistry; D010450:Endopeptidases / Q000494:pharmacology; D005656:Fungal Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D005780:Gelatin; D005800:Genes, Fungal; D006026:Glycoside Hydrolases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D012331:RNA, Fungal / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000254:growth & development; D013696:Temperature; D013997:Time Factors; D043324:beta-Fructofuranosidase
D003470:Culture Media; D005656:Fungal Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D005780:Gelatin; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase; D010450:Endopeptidases