Hydrolysis of leaf Fraction 1 protein by the proteolytic rumen bacterium Bacteroides ruminicola R8/4.
Proteolytic activity in a batch culture of Bacteroides ruminicola R8/4 was maximal and largely (greater than 90%) cell-associated during the mid-exponential phase of growth. The cell-bound protease was not inactivated during storage at --70% C, was not significantly affected by pH over the range 5.9 to 8.2, but was subject to substrate inhibition by Fraction 1 protein (ribulose-1,5-bisphosphate carboxylase; EC 4.1.1.39) and was most active in the presence of thiol reagents. Radioactive Fraction 1 protein was hydrolysed by non-growing and growing cells of B. ruminicola R8/4 with the production of peptides and free amino acids. Deaminase activity was absent. Radioactive amino acids were incorporated into bacterial proteins from [14C]Fraction 1 protein without substantial change in specific radioactivity.
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001439:Bacteroides / Q000254:growth & development / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000378:metabolism*; D004044:Dietary Proteins / Q000378:metabolism*; D006868:Hydrolysis; D010447:Peptide Hydrolases / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism*; D012417:Rumen / Q000382:microbiology*; D013438:Sulfhydryl Compounds / Q000494:pharmacology
D000596:Amino Acids; D004044:Dietary Proteins; D010940:Plant Proteins; D013438:Sulfhydryl Compounds; D010447:Peptide Hydrolases; D002262:Carboxy-Lyases; D012273:Ribulose-Bisphosphate Carboxylase