Lactobacillus plantarum amylase acting on crude starch granules. Native isoforms and activity changes after limited proteolysis.
The microheterogeneous native amylolytic complex secreted by the isolate A6 of Lactobacillus plantarum revealed a selective enzyme specificity loss when submitted to a limited proteolysis under a suboptimum pH condition. A clear electrophoretic profile change toward just one shorter, more acidic, and equally active polypeptide fragment resulted from the pronase E pretreatment. Although the whole enzyme activity remained apparently unaffected for soluble starch, the native parallel activity on intact and non-gelatinized starch granules either from cereals or tubers was dramatically reduced. This phenomenon was more clearly documented by scanning electron microscopy using the easiest accessible native substrate: wheat starch granules. The anion-exchange-purified native enzymes from L. plantarum displayed a different optimum pH curve when compared with the thermotolerant alpha-amylase from Bacillus licheniformis. The alpha-amylases from the lactic-acid-producing A6 isolate presented an electrophoretic profile easily distinguishable from those from B. liqueniformis and B. subtilis species.
Florêncio
J A
JA
Department of Biochemistry, UFPR-Federal University of Paraná, Curitiba, PR, Brazil.
Eiras-Stofella
D R
DR
Soccol
C R
CR
Raimbault
M
M
Guyot
J P
JP
Fontana
J D
JD
D000681:Amylases / Q000737:chemistry / Q000378:metabolism*; D018533:Biomass; D050260:Carbohydrate Metabolism; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D019344:Lactic Acid / Q000378:metabolism; D007778:Lactobacillus / Q000201:enzymology* / Q000254:growth & development; D010446:Peptide Fragments / Q000378:metabolism; D011402:Pronase; D013213:Starch / Q000378:metabolism* / Q000648:ultrastructure; D014908:Triticum
D007527:Isoenzymes; D010446:Peptide Fragments; D019344:Lactic Acid; D013213:Starch; D000681:Amylases; D011402:Pronase