Eigenschaften der Carboxypeptidase C aus Orangenblättern

Sprössler, Bruno; Heilmann, Hans-Dietrich; E, Grampp; Uhlig, Helmut

doi:10.1515/bchm2.1971.352.2.1524

Cited by 29 publications

(5 citation statements)

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“…Plant stems and leaves have also been shown to contain serine carboxypeptidases (41,49,171,191) and in one of these cases wounding of a single leaf caused a three fold increase of carboxypeptidase activity in other unwounded leaves ( 191 ).…”

Section: Serine Earboxypeptidases In Higher Plantsmentioning

confidence: 99%

Serine carboxypeptidases. A review

Breddam

1986

Carlsberg Res. Commun.

180

130

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Carboxypeptidases are proteolytic enzymes which only cleave the C-terminal peptide bond in polypeptides. Those characterized until now can, dependent on their catalytic mechanism, be classified as either metallo carboxypeptidases or as serine carboxypeptidases. Enzymes from the latter group are found in the vacuoles of higher plants and fungi and in the lysosomes of animal cells. Many fungi, in addition, excrete serine carboxypeptidases. Apparently, bacteria do not employ this group of enzymes.Most serine carboxypeptidases presumably participate in the intracellular turnover of proteins and some of them, in addition, release amino acids from extracellular proteins and peptides. However, prolyl carboxypeptidase which cleaves the C-terminal peptide bond of angiotensin II and III is a serine carboxypeptidase with a more specific function.Serine carboxypeptidases are usually glycoproteins with subunit molecular weights of 40,000 -75,000. Those isolated from fungi apparently contain only a single peptide chain while those isolated from higher plants and animals in most cases contain two peptide chains linked by disulfide bridges. However, a number of the enzymes aggregate forming dimers and oligomers.It is probable that the well-known catalytic mechanism of the serine endopeptidases is also employed by the serine carboxypeptidases but presumably with the difference that the plQ of the catalytically essential histidyl residue is somewhat lower in the carboxypeptidases than in the endopeptidases. However, the leaving group specificity of these two groups of enzymes differ since the carboxypeptidases only release C-terminal amino acids from peptides (peptidase activity) and not longer peptide fragments. In addition, they release C-terminal amino acid amides (peptidyl amino acid amide hydrolase activity) or ammonia (amidase activity) from peptide amides and alcohols from peptide esters (esterase activity) and this property they share with the serine endopeptidases. Like other proteolytic enzymes the serine carboxypeptidases contain binding sites which secure the interaction between enzyme and substrate. In this laboratory, the properties of these have been studied for three serine carboxypeptidases, i.e. carboxypeptidase Y from yeast and malt carboxypeptidases I and II, by means of kinetic studies, chemical modifications of amino acid side-chains located at these binding sites and exchange of such amino acid residues by site-directed mutagenesis.Serine carboxypeptidases, such as carboxypeptidase Y and malt carboxypeptidase II which are available in large quantities, can be applied for several purposes. Their broad specificity and ability to release amino acids from the C-terminus of a peptide chain can be employed in determination of amino acid sequences, and their ability to catalyze transpeptidation reactions and aminolysis ofpeptide esters can be employed to exchange C-terminal amino acid residues in peptides and in step-wise synthesis ofpolypeptides, respectively. The type of reactions catalyzed by these enzymes is l...

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Section: Serine Earboxypeptidases In Higher Plantsmentioning

confidence: 99%

Serine carboxypeptidases. A review

Breddam

1986

Carlsberg Res. Commun.

180

130

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“…Only one proteolytic activity (carboxypeptidase C) has hitherto been characterized in Citrus leaves (Sprossler et al 1971, Zaber 1976. Our results do not allow us to identify the carboxypeptidase C among the four proteolytic activities described above.…”

Section: Diseussionmentioning

confidence: 99%

“…Our results do not allow us to identify the carboxypeptidase C among the four proteolytic activities described above. However, it could be tentatively assigned to type 1 due to the lack of influence of EDTA or thiols on the carboxypeptidase C activity (Sprossler et al 1971).…”

Section: Diseussionmentioning

confidence: 99%

Proteolysis of ribulose‐1,5‐bisphosphate carboxylase/oxygenase in Citrus leaf extracts

Garcı́a-Martı́nez¹,

Moreno²

1986

Physiologia Plantarum

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Ribulose‐1,5‐bisphosphate carboxylase/oxygenase (RuBP carboxylase, EC 4.1.1.39) has been purified from orange [Citrus sinensis (L.) Osbeck cv. Washington Navel] leaves using sucrose gradient centrifugation in a fixed angle rotor. Following sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE), two major bands corresponding to the two subunits of RuBP carboxylase were found. The large subunit coincided with the polypeptide band that has been previously reported to be preferentially mobilized during the spring and summer flush periods. The degradation of RuBP carboxylase during autodigestion of Citrus leaf extracts, investigated by SDS‐PAGE, occurred mainly at acidic (2.5‐5.5) pH. The two subunits showed differences in the rate of degradation, the smaller being more rapidly hydrolyzed than the larger. At least four proteolytic activities were identified by means of inhibitor experiments: 1) a pepstatin A‐sensitive activity that acts on both RuBP carboxylase subunits, 2) a mercurial (p‐hydroxymercuribenzoate and p‐chloromercuriphenylsulfonate)‐sensitive activity that degrades only the small subunit, 3) an EDTA‐sensitive activity that hydrolyzes both the large and small subunits, and 4) a mercurial‐stimulated activity that acts only on the large subunit. It is suggested that the last two proteases may be responsible for the degradation of RuBP carboxylase observed in vivo during the periods of mobilization of leaf protein in Citrus.

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“…Their presence has been observed in a number of higher plants, in the horsetail, Eqidsetum (Zuber and Matile 1968), and also in a green alga, Nitella (Doi et al 1975). Higbly purified preparations have been obtained and characterized from Citrus peel (Zuber 1968, Kubota et al 1973, Citrus leaves (Sprossler et al 1971), young shoots of Phaseolus (Wells 1965(Wells , 1968, germinating seeds of barley (Visuri et al 1969, Moeller et al 1970) and cotton (Ihle and Dure 1972a,b). Corresponding enzymes have been observed and purified from baker 's yeast (e.g.…”

Section: Introductionmentioning

confidence: 99%

Localization and Activity of a Carboxypeptidase in Germinating Seeds of Scots Pine, Pinus sylvestris

Salmia

Mikola

1976

Physiologia Plantarum

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Extracts prepared from the endosperm of germinating seeds of Scots pine, Pinus sylvestris L., hydrolysed two typical carboxypeptidase substrates, Z‐Phe‐Ala and Z‐Phe‐Phe, with pH optima at 4.2 and 5.0. The activities were completely destroyed by diisopropylfluorophosphate. Identical heat inactivation curves and elution patterns in gel chromatography on Sephadex G‐200 suggest that the two activities are due to a single enzyme. In resting seeds very low carboxypeptidase activity was present in both the endosperm and the embryo. During germination on agar gel at 20°C in the dark the activities, expressed as enzyme units per seed, increased in the seedling and particularly in the endosperm up to the stage when the reserves of the endosperm were completely depleted. The time of rapid increase of activity in the endosperm did not coincide with the onset of storage protein mobilization. On the contrary, the major part of the increase occurred after the bulk of endosperm nitrogen had already been transferred to the seedling. The results suggest that the carboxypeptidase does not play a major role in the mobilization of storage proteins in germinating pine seeds. On the other hand, it probably functions in the proteolytic reactions associated with the senescence of the reserve‐depleted endosperm.

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Eigenschaften der Carboxypeptidase C aus Orangenblättern

Cited by 29 publications

References 0 publications

Serine carboxypeptidases. A review

Serine carboxypeptidases. A review

Proteolysis of ribulose‐1,5‐bisphosphate carboxylase/oxygenase in Citrus leaf extracts

Localization and Activity of a Carboxypeptidase in Germinating Seeds of Scots Pine, Pinus sylvestris

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