Biomaterial Database

Successive amino-terminal proteolysis of the large subunit of ribulose 1,5-biphosphate carboxylase/oxygenase by vacuolar enzymes from French bean leaves. 1996

T Yoshida, and T Minamikawa

Department of Biology, Tokyo Metropolitan University, Japan.

Mainly using the protein immunoblot technique, we observed the decrease in amounts of the large subunit (LSU) and the small subunit (SSU) of ribulose 1,5-biphosphate carboxylase/oxygenase (Rubisco) in detached primary leaves of French bean plants during senescence under the light or in darkness, but detected no significant degradation products of these subunits. Treatment of the detached leaves with 0.6% (mass/vol.) dimethyl sulfoxide, 0.05% (mass/vol.) Tween 80 considerably promoted the senescence, as estimated by the reduction in content of the soluble protein, and also in the amounts of LSU and SSU, but no degradation product of either subunit was found. When extracts prepared from the primary leaves were incubated at pH 5.4 or pH 7.4, the amount of LSU of 53 kDa decreased and concurrently 50-kDa and 42-kDa polypeptides were formed. Since the results suggested that Rubisco may be degraded by vacuolar enzymes, we incubated Rubisco with vacuolar lysates prepared from the senescing primary leaves and found that the LSU, but not SSU, was degraded to a 41-kDa polypeptide through three intermediates of 50 kDa, 48 kDa and 42 kDa. Determination of amino-terminal amino acid sequences of these fragments indicated that each of the proteolysis steps occurred by removal of a small amino-terminal peptide. Experiments with various inhibitors of proteases as well as with a purified Vigna mungo vacuolar protease, termed SH-EP [Mitsuhashi, W. & Minamikawa, T. (1989) Plant Physiol. 89, 274-279] suggested the involvement of two types of proteases in these steps: a cysteine protease that is the same type of enzyme as SH-EP catalyzes the steps from the LSU to the 48-kDa polypeptide through the 50-kDa polypeptide, and a serine protease catalyzes the steps from the 48-kDa polypeptide to the 41-kDa polypeptide through the 42-kDa polypeptide.

UI	MeSH Term	Description	Entries
D007887	Fabaceae	The large family of plants characterized by pods. Some are edible and some cause LATHYRISM or FAVISM and other forms of poisoning. Other species yield useful materials like gums from ACACIA and various LECTINS like PHYTOHEMAGGLUTININS from PHASEOLUS. Many of them harbor NITROGEN FIXATION bacteria on their roots. Many but not all species of "beans" belong to this family.	Afzelia,Amorpha,Andira,Baptisia,Callerya,Ceratonia,Clathrotropis,Colophospermum,Copaifera,Delonix,Euchresta,Guibourtia,Legumes,Machaerium,Pithecolobium,Stryphnodendron,Leguminosae,Pea Family,Pithecellobium,Tachigalia,Families, Pea,Family, Pea,Legume,Pea Families
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010946	Plants, Medicinal	Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.	Herbs, Medicinal,Medicinal Herbs,Healing Plants,Medicinal Plants,Pharmaceutical Plants,Healing Plant,Herb, Medicinal,Medicinal Herb,Medicinal Plant,Pharmaceutical Plant,Plant, Healing,Plant, Medicinal,Plant, Pharmaceutical,Plants, Healing,Plants, Pharmaceutical
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D003517	Cyclopentanes	A group of alicyclic hydrocarbons with the general formula R-C5H9.	Cyclopentadiene,Cyclopentadienes,Cyclopentene,Cyclopentenes,Cyclopentane
D003546	Cysteine Endopeptidases	ENDOPEPTIDASES which have a cysteine involved in the catalytic process. This group of enzymes is inactivated by CYSTEINE PROTEINASE INHIBITORS such as CYSTATINS and SULFHYDRYL REAGENTS.
D004591	Electrophoresis, Polyacrylamide Gel	Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.	Polyacrylamide Gel Electrophoresis,SDS-PAGE,Sodium Dodecyl Sulfate-PAGE,Gel Electrophoresis, Polyacrylamide,SDS PAGE,Sodium Dodecyl Sulfate PAGE,Sodium Dodecyl Sulfate-PAGEs
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000085	Acetates	Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.	Acetate,Acetic Acid Esters,Acetic Acids,Acids, Acetic,Esters, Acetic Acid
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein