Conformation and processing of cathepsin D

1985 ◽  
Vol 5 (10-11) ◽  
pp. 957-967 ◽  
Author(s):  
Roger H. Pain ◽  
Tamara Lan ◽  
Vito Turk
Keyword(s):  
Enzyme Activity ◽  
Protein Turnover ◽  
Cathepsin D ◽  
Polypeptide Chain ◽  
Proteolytic Processing ◽  
Single Polypeptide Chain ◽  
Processing Step ◽  
Acid Environment ◽  
Single Polypeptide ◽  
Covalent Complex

Cathepsin D occurs in two forms, a single polypeptide chain (Mr 44000) and a non-covalent complex of two peptides of Mr 14000 and 30000 that is derived by proteolytic processing of the 44000 polypeptide. The two forms from bovine spleen are closely similar in secondary structure content, in aromatic amino acid environment and in the two step denaturation behaviour. Enzyme activity is lost irreversibly on denaturation but conformation can be partially regained. The two separated chains will only refold partially and this is related to their positions in the overall structure of cathepsin D. It is suggested that the processing step is related to protein turnover.

scholarly journals Conformation, structure and activation of bovine cathepsin D. Unfolding and refolding studies

1984 ◽  
Vol 218 (2) ◽  
pp. 601-608 ◽  
Author(s):  
T Lah ◽  
M Drobniĉ-Koŝorok ◽  
V Turk ◽  
R H Pain
Keyword(s):  
Cathepsin D ◽  
Specific Activity ◽  
Single Chain ◽  
Guanidinium Chloride ◽  
Single Polypeptide Chain ◽  
Acid Environment ◽  
Single Polypeptide ◽  
Kinetics Of ◽  
Chain Form ◽  
Covalent Complex

Cathepsin D is found in the cell in two forms, one a single polypeptide chain (Mr 44 000) and the other a non-covalent complex of two peptides of Mr 14 000 and 30 000. These correspond to the N-terminal and C-terminal regions of the single chain from which they originate. It has been shown that the two forms of the enzyme are closely similar in secondary-structure content, in aromatic amino acid environment and in denaturation behaviour. The two-chain enzyme has half the specific activity of the single-chain form. The denaturation and renaturation of the single-chain cathepsin D has now been studied by c.d., fluorescence and enzyme activity. Activity is lost irreversibly on unfolding, but the loss of backbone ellipticity and of folded aromatic environment is 75% reversible. The enzyme unfolds in two main stages, and the kinetics of these transitions indicate the existence of at least two intermediate forms between the native and the fully unfolded states. A further form of the enzyme exists in 0.5 M-guanidinium chloride. It is characterized by having an activity 40% greater than that of the native state. This increase is not reversed on removing the denaturant. The similarities between cathepsin D and pepsin are discussed.

Debranching enzyme from rabbit skeletal muscle; Evidence for the location of two active centres on a single polypeptide chain

FEBS Letters ◽  
1975 ◽  
Vol 58 (1-2) ◽  
pp. 181-185 ◽  
Author(s):  
Edna J. Bates ◽  
Gillian M. Heaton ◽  
Carol Taylor ◽  
John C. Kernohan ◽  
Philip Cohen
Keyword(s):  
Skeletal Muscle ◽  
Polypeptide Chain ◽  
Rabbit Skeletal Muscle ◽  
Debranching Enzyme ◽  
Single Polypeptide Chain ◽  
Single Polypeptide ◽  
Active Centres

scholarly journals Hepatic microsomal epoxide hydrase. Chemical evidence for a single polypeptide chain.

1979 ◽  
Vol 254 (14) ◽  
pp. 6240-6243 ◽  
Author(s):  
G C DuBois ◽  
E Appella ◽  
R Armstrong ◽  
W Levin ◽  
A Y Lu ◽  
...  
Keyword(s):  
Polypeptide Chain ◽  
Single Polypeptide Chain ◽  
Single Polypeptide ◽  
Chemical Evidence

scholarly journals Identification of Igh-C-linked determinants on suppressor T cell hybrids and factors specific for L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT).

1985 ◽  
Vol 162 (3) ◽  
pp. 1044-1059 ◽  
Author(s):  
C M Sorensen ◽  
R J Hayashi ◽  
C W Pierce
Keyword(s):  
T Cells ◽  
T Cell ◽  
Polypeptide Chain ◽  
Spleen Cells ◽  
Suppressor T Cell ◽  
Cell Hybrids ◽  
Single Polypeptide Chain ◽  
Functional Classes ◽  
Single Polypeptide ◽  
Ig Allotype

Hyperimmunization of BALB/c mice with concanavalin A-stimulated blasts from the Ig allotype-congenic strain, C.B20, results in the production of antibodies reactive with T cells in an allotype-restricted manner. Spleen cells from these hyperimmune BALB/c mice were used to generate a panel of hybridomas that secrete monoclonal antibodies, reactive, in an allotype-restricted manner, exclusively with T cells subpopulations, and in particular, reactive with suppressor T cell hybridomas and their secreted soluble factors. Two functional classes of antibodies were identified: those that react with single polypeptide-chain suppressor T cell factors (TsF1) and the suppressor T cell hybridomas that produce such factors, and those that react with two polypeptide-chain suppressor T cell factors (TsF2) and their corresponding suppressor T cell hybridomas. These two classes of antibody were used to isolate molecules from the membranes of the respective suppressor T cell hybrids that are functionally and structurally related to the secreted suppressor T cell factors, suggesting a receptor function for these molecules.

The power of the force: mechano-physiology of the giant titin

2018 ◽  
Vol 2 (5) ◽  
pp. 681-686 ◽  
Author(s):  
Jaime Andrés Rivas-Pardo
Keyword(s):  
Amino Acid ◽  
Human Body ◽  
Actin Filaments ◽  
Polypeptide Chain ◽  
Single Gene ◽  
The Other ◽  
Amino Acid Residues ◽  
The Third ◽  
Single Polypeptide Chain ◽  
Single Polypeptide

Titin — the largest protein in the human body — spans half of the muscle sarcomere from the Z-disk to the M-band through a single polypeptide chain. More than 30 000 amino acid residues coded from a single gene (TTN, in humans Q8WZ42) form a long filamentous protein organized in individual globular domains concatenated in tandem. Owing to its location and close interaction with the other muscle filaments, titin is considered the third filament of muscle, after the thick-myosin and the thin-actin filaments.

scholarly journals The purification and some properties of rusticyanin, a blue copper protein involved in iron(II) oxidation from Thiobacillus ferro-oxidans

1978 ◽  
Vol 174 (2) ◽  
pp. 497-502 ◽  
Author(s):  
J C Cox ◽  
D H Boxer
Keyword(s):  
Polypeptide Chain ◽  
Iron Oxidation ◽  
Exchange Chromatography ◽  
Blue Copper Protein ◽  
Blue Copper ◽  
Copper Protein ◽  
Optical Absorbance ◽  
Single Polypeptide Chain ◽  
Arginine Residues ◽  
Single Polypeptide

The ‘blue’ copper-containing protein rusticyanin was purified to homogeneity from cells of the chemolithotrophic bacterium Thiobacillus ferro-oxidans by (NH4)SO4 fractionation and ion-exchange chromatography. The protein, which is stable at low pH, consists of a single polypeptide chain of mol. wt. 16500 and possesses 0.79 (+/- 0.28)g-atom of Cu/mol. The protein, which does not contain arginine residues, has optical absorbance maxima at 287, 450, 597 and 750 nm and is generally similar to azurin. The isolated protein is reduced directly by Fe2+ with a 1:1 stoicheiometry to Cu. On reduction by Fe2+ the absorption peaks at 450, 597 and 750 nm are abolished, with the appearance of a new absorption band at 320 nm. The results obtained are consistent with rusticyanin being the initial acceptor of electrons from Fe2+ during respiratory iron oxidation.

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