scholarly journals Limited proteolysis of complement components C2 and factor B. Structural analogy and limited sequence homology

1979 ◽  
Vol 183 (3) ◽  
pp. 615-622 ◽  
Author(s):  
M A Kerr
Keyword(s):  
Sequence Homology ◽  
Polyacrylamide Gel Electrophoresis ◽  
Limited Proteolysis ◽  
Gel Filtration ◽  
Serine Proteinase ◽  
Terminal Sequence ◽  
Complement Components ◽  
Factor B ◽  
Terminal Residue ◽  
Covalently Linked

A method is described for the simultaneous purification of milligram quantities of complement components C2 and Factor B. Both products are homogeneous by the criteria of polyacrylamide-gel electrophoresis and N-terminal sequence analysis. Component C2 is cleaved by serine proteinase C1s at an X-Lys bond to give fragment C2a (approx. mol.wt. 74000) and fragment C2b (approx. mol.wt. 34000). The two fragments can be separated by gel filtration without the need for reducing or denaturing agents. Fragment C2b represents the N-terminal end of the molecule. Similar results were seen on cleavage of Factor B by Factor D in the presence of component C3. Again two non-covalently linked fragments are formed. The smaller, fragment Ba (approx. mol.wt. 36,000),) has threonine as the N-terminal residue, as does Factor B; the larger, fragment Bb (approx. mol. wt. 58000), has lysine as the N-terminal residue. A similar cleavage pattern is obtained on limited proteolysis of Factor B by trypsin, suggesting an Arg-Lys-or Lys-Lys bond at the point of cleavage. Although component C2 and Factor B show no apparent N-terminal sequence homology, a limited degree of sequence homology is seen around the sites of proteolytic cleavage.

scholarly journals Subunit structure of Vicia graminea anti-(blood-group N) lectin

1980 ◽  
Vol 189 (1) ◽  
pp. 185-188 ◽  
Author(s):  
M J Prigent ◽  
R Bourrillon
Keyword(s):  
Blood Group ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Subunit Structure ◽  
Terminal Sequence ◽  
Guanidinium Chloride ◽  
Molecular Weights ◽  
Covalently Linked

The subunit of the Vicia graminea lectin with blood-group-N specificity was examined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and gel filtration in 6M-guanidinium chloride, and its molecular weights was found to be 25 000. The unique N-terminal sequence fof the first nine residues of the lectin confirmed that Vicia lectin consists of four identical chains non-covalently linked. Finally the microheterogeneity of the lectin shown by analytical isoelectric focusing is discussed.

Characterization of serine proteinase inhibitors in dry seeds of cultivated pasture grass species

1994 ◽  
Vol 4 (3) ◽  
pp. 335-345 ◽  
Author(s):  
Mohammed Tasneem ◽  
Clive A. Cornford ◽  
Michael T. McManus
Keyword(s):  
Festuca Arundinacea ◽  
Proteinase Inhibitors ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Serine Proteinase ◽  
Grass Species ◽  
Pasture Grass ◽  
Molecular Weights ◽  
Trypsin Inhibition ◽  
Pasture Grasses

AbstractA survey of proteinaceous inhibitors of the serine proteinases, bovine trypsin and chymotrypsin, that are extractable from dry seeds of several cultivars of pasture grasses has been undertaken. Using crude extracts, most cultivars screened contained inhibitors of chymotrypsin, whereas trypsin inhibition was not detectable. Seeds from four cultivars, Lolium perenne L. cv. Grasslands Ruanui, Lolium × boucheanum cv. Grasslands Greenstone, Festuca arundinacea Schreb. cultivars Grasslands Roa and Grasslands Garland, that contained more potent chymotrypsin inhibition were purified further. After gel filtration chromatography, both trypsin and chymotrypsin inhibition could be observed in all four cultivars, and each separated into two discrete native molecular weights; one of ca. 20–22 kDa and one of ca. 8–10 kDa. However, activity staining, after polyacrylamide gel electrophoresis, revealed an array of iso-inhibitors with molecular weights that ranged from ca. 3 kDa to 20 kDa. One of these, a dual trypsin/chymotrypsin inhibitor of ca. 12 kDa that is present in all four cultivars examined, was purified to homogeneity from F. arundinacea cv. Grasslands Garland using anhydro-trypsin affinity chromatography and reverse-phase HPLC. The protein was found to comprise two closely related peptides and N-terminal amino acid sequencing revealed highest identity with a trypsin inhibitor identified in rye (Secale cereale) seeds.

scholarly journals Procollagenase activator produced by rabbit uterine cervical fibroblasts

1987 ◽  
Vol 241 (2) ◽  
pp. 527-534 ◽  
Author(s):  
M Ishibashi ◽  
A Ito ◽  
K Sakyo ◽  
Y Mori
Keyword(s):  
Culture Medium ◽  
Proteinase Inhibitors ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Limited Proteolysis ◽  
Serine Proteinase ◽  
Active Species ◽  
Rabbit Plasma ◽  
Neutral Proteinase ◽  
Type Iv

Culture medium from rabbit uterine cervical fibroblasts contained a procollagenase and a neutral proproteinase which acts as a procollagenase activator. These two proenzymes have been purified by a combination of ion-exchange, affinity and gel chromatographies. The purified neutral proproteinase showed Mr 60,000 with sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. This neutral proproteinase was activated by trypsin, 4-aminophenylmercuric acetate (APMA) and plasmin, and the active species of the proteinase had Mr 53,000 when activated by APMA; kallikrein and urokinase did not activate this proproteinase. The purified neutral proteinase was inhibited by EDTA, 1,10-phenanthroline and rabbit plasma, but not by serine proteinase inhibitors, suggesting that this proteinase is a metal-dependent proteinase. The purified enzyme could also degrade gelatin, casein, proteoglycan and type IV procollagen. The purified procollagenase had Mr 55,000 and was activated by trypsin, APMA and the active neutral proteinase. These activations were accompanied by decrease in Mr, and the activated species had an Mr which was approx. 10,000 less than that of the procollagenase. In particular, procollagenase activation with neutral proteinase depended on incubation time and proteolytic activity of proteinase. These results indicate that activation of procollagenase by the rabbit uterine neutral proteinase is related to limited proteolysis in the procollagenase molecule.

scholarly journals Purification and biochemical characterization of three major acidic proteins (BSP-A1, BSP-A2 and BSP-A3) from bovine seminal plasma

1987 ◽  
Vol 241 (3) ◽  
pp. 685-692 ◽  
Author(s):  
P Manjunath ◽  
M R Sairam
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Seminal Plasma ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Polyacrylamide Gel ◽  
Terminal Residue ◽  
Acidic Proteins

Three major acidic proteins of bovine seminal plasma, BSP-A1, BSP-A2 and BSP-A3, were purified to homogeneity, by employing fast protein liquid chromatography, gel filtration and h.p.l.c. The proteins were purified on the basis of their stimulatory effect on the basal release of gonadotropins by rat anterior-pituitary cells in culture. All three proteins migrated as distinct single bands in the presence or absence of 2-mercaptoethanol in SDS/polyacrylamide-gel electrophoresis. Their Mr values were estimated to be between 15,000 and 16,500 by SDS/polyacrylamide-gel electrophoresis. Similar Mr estimates were obtained when they were subjected to gel filtration on a calibrated column of Sephadex G-75 equilibrated in 0.05 M-acetic acid, pH 3.0. However, BSP-A1 and BSP-A2 were eluted as aggregated molecules (Mr 60,000-120,000) during gel filtration on Sephadex G-200 equilibrated in 0.05 M-NH4HCO3, pH 8.5, or phosphate buffer, pH 7.0, containing 0.15 M-NaCl. In the presence of 8 M-urea both BSP-A1 and BSP-A2 were eluted at positions corresponding to Mr values of 17,000-20,000. BSP-A1 and BSP-A2 had an identical amino acid composition, which differed largely from that of BSP-A3. All three proteins contained aspartic acid as the N-terminal residue, and cysteine was identified as the C-terminal residue. BSP-A1 and BSP-A2 are glycoproteins containing galactosamine, sialic acid and neutral sugars, but BSP-A3 did not contain any covalently attached sugars. Whereas BSP-A2 and BSP-A3 were eluted unadsorbed, BSP-A1 bound to wheat-germ lectin-Sepharose 6MB and could be eluted by the competing sugar N-acetyl-D-glucosamine. Treatment of BSP-A1 and BSP-A2 with trypsin resulted in complete loss of gonadotropin-release activity, but BSP-A3 retained full activity. Antibody raised against BSP-A1 did not cross-react with BSP-A3, or vice versa. All these properties indicated marked structural differences between BSP-A3 and BSP-A1 (or BSP-A2). On the basis of amino acid composition it was concluded that BSP-A1, BSP-A2 and BSP-A3 are the same as the gonadostatins [Esch, Ling, Bohlen, Ying & Guillemin (1983) Biochem. Biophys. Res. Commun. 113, 861-867].

An N-terminal partial sequence of the 13 kDa Pycnopodia helianthoides sperm chemoattractant 'startrak' possesses sperm-attracting activity.

1996 ◽  
Vol 199 (2) ◽  
pp. 311-318 ◽  
Author(s):  
R L Miller ◽  
R Vogt
Keyword(s):  
Molecular Mass ◽  
Synthetic Peptide ◽  
Direct Sequencing ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Hydrophobic Interaction Chromatography ◽  
Partial Sequence ◽  
Terminal Sequence ◽  
Sperm Chemotaxis ◽  
Single Peptide

Freshwater extracts of starfish ovaries were used to purify the sperm-attracting peptide 'startrak' from Pycnopodia helianthoides using hydrophobic interaction chromatography and DEAE-high-pressure liquid chromatography. Partially purified attractant had a molecular mass of 13 kDa, estimated from gel filtration and polyacrylamide gel electrophoresis results. The purified attractant was subjected to amino acid analysis and direct sequencing, and was found to consist largely of a single peptide composed of an estimated 127 residues based on a molecular mass of 13kDa. An N-terminal sequence of amino acids from positions 3 to 34 was obtained and synthesized as: NH2-Ala-Glu-Leu-Gly-Leu-Cys-Ile-Ala-Arg-Val-Arg-Gln-Gln-Asn-Gln-Gly-Gln- Asp-Asp-Val-Ser-Ile-Tyr-Gln-Ala-Ile-Met-Ser-Gln-Cys-Gln-Ser-COOH. The synthetic peptide possessed sperm-attracting activity 130 times greater than the activity of partially purified startrak and showed a pattern of species-specificity of sperm chemotaxis similar to that of startrak. Antibody prepared against synthetic peptide removed the sperm-attracting activity from crude and partially purified preparations of startrak. The partial sequence of startrak was not homologous with that of any of the known echinoid sperm motility-activating peptides.

scholarly journals Purification of a metalloproteinase inhibitor from human rheumatoid synovial fluid

1985 ◽  
Vol 231 (3) ◽  
pp. 505-510 ◽  
Author(s):  
E Mercer ◽  
T E Cawston ◽  
M de Silva ◽  
B L Hazleman
Keyword(s):  
Synovial Fluid ◽  
Culture Medium ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Serine Proteinase ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Metalloproteinase Inhibitor ◽  
Bacterial Collagenase ◽  
Rheumatoid Synovial Fluid

A metalloproteinase inhibitor present in human rheumatoid synovial fluid was purified by a combination of heparin-Sepharose chromatography, concanavalin A-Sepharose chromatography, ion-exchange chromatography and gel filtration. The Mr of the purified inhibitor was 28000 by SDS/polyacrylamide-gel electrophoresis and 30000 by gel filtration. The inhibitor blocked the activity of the metalloproteinases collagenase, gelatinase and proteoglycanase, but not thermolysin or bacterial collagenase. The serine proteinase trypsin was not inhibited. The inhibitory activity was lost after treatment with trypsin (0.5 micrograms/ml) at 37 degrees C for 30 min, 4-aminophenylmercuric acetate (1 mM) at 37 degrees C for 3 h, after incubation for 30 min at 90 degrees C and by reduction and alkylation. These properties suggest that the inhibitor closely resembles the tissue inhibitor of metalloproteinases (‘TIMP’) recently purified from connective-tissue culture medium.

scholarly journals Evolution of α2-macroglobulin. The structure of a protein homologous with human α2-macroglobulin from plaice (Pleuronectes platessa L.) plasma

1982 ◽  
Vol 205 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Phyllis M. Starkey ◽  
Alan J. Barrett
Keyword(s):  
Peptide Mapping ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Polyacrylamide Gel ◽  
Complement Components ◽  
Pleuronectes Platessa ◽  
Reducing Conditions ◽  
Α2 Macroglobulin ◽  
Mild Reduction ◽  
Covalently Linked

The plaice (Pleuronectes platessa L.) papain-binding protein previously demonstrated to be homologous with human α2-macroglobulin, and designated plaice α2-macroglobulin homologue or αMh, was shown to be a glycoprotein of s20,w 11.86S. In polyacrylamide-gel pore-limit electrophoresis under non-denaturing conditions plaice αMh migrated to the same position as half-molecules of human α2-macroglobulin, and treatment with methylamine or a proteinase caused no change in its electrophoretic properties. Either denaturation in urea (4m) or mild reduction by dithiothreitol (1mm) partially dissociated plaice αMh into half-molecules. Denaturation with reduction further dissociated the protein into quarter-subunits. In sodium dodecyl sulphate/polyacrylamide-gel electrophoresis under reducing conditions plaice αMh dissociated into subunits of Mr 105000 (I) and 90000 (II). Approximately equal amounts of each subunit were formed, and peptide ‘mapping’ showed subunits I and II to be distinct polypeptide chains. Under alkaline denaturing conditions, a proportion of the I chains of αMh were cleaved into fragments of Mr about 60000 and 40000. This cleavage was favoured by reducing conditions and prevented by prior inactivation of the αMh with methylamine. [14C]Methylamine allowed to react with αMh became covalently linked to subunit I. These properties suggested the existence of an autolytic site on subunit I analogous to the autolytic site of human α2-macroglobulin. Reaction of αMh with a proteinase resulted in cleavage of a fragment of Mr 10000–15000 from subunit I. A proportion of the proteinase molecules trapped by αMh became covalently linked to the inhibitor. A scheme is proposed for the evolution of human α2-macroglobulin and plaice αMh from a common ancestral protein, which may also have been an ancestor of complement components C3 and C4.

scholarly journals The induction of macrophage spreading by factor B of the properdin system.

1979 ◽  
Vol 149 (2) ◽  
pp. 372-386 ◽  
Author(s):  
O Götze ◽  
C Bianco ◽  
Z A Cohn
Keyword(s):  
Alternative Pathway ◽  
Polyacrylamide Gel Electrophoresis ◽  
Serine Proteinase ◽  
Cell Spreading ◽  
Peritoneal Macrophages ◽  
Mononuclear Phagocytes ◽  
Mouse Serum ◽  
Factor B ◽  
Mouse Macrophages ◽  
Alternative Pathway Of Complement

Unstimulated mouse peritoneal macrophages attached to a glass substratum responded to activated human factor B (Bb) of the properdin system but not to native factor B with rapid spreading and a concomitant increase in their apparent surface area. Excellent correlation of the distribution of Bb protein and cell-spreading activity was found upon purification of Bb by ion-exchange and molecular seive chromatography and alkaline polyacrylamide gel electrophoresis. 1.6 microgram of purified Bb was sufficient to induce spreading in 50% of 5 x 10(4) glass attached macrophages within 1-2 h at 37 degrees C. Treatment of Bb with di-isopropyl-fluorophosphate indicated that the intact catalytic site of the serine-proteinase Bb was required for the initiation of macrophage spreading. The involvement of factor B in the induction of rapid cell spreading could also be indirectly demonstrated in an autologous system in which F(ab')2 fragments of an antiserum to mouse B prevented mouse macrophages from spreading in response to complement-activated mouse serum. These experiments suggest a role for factor B and the alternative pathway of complement fixation in the localization of mononuclear phagocytes to areas of inflammation.

scholarly journals The inactivation of native enzymes by a neutral proteinase from rat intestinal muscle

1978 ◽  
Vol 173 (1) ◽  
pp. 291-298 ◽  
Author(s):  
R J Beynon ◽  
J Kay
Keyword(s):  
Smooth Muscle ◽  
Proteolytic Enzymes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Limited Proteolysis ◽  
Serine Proteinase ◽  
Partial Purification ◽  
Intestinal Smooth Muscle ◽  
Bean Trypsin Inhibitor ◽  
Ph Range

1. The solubilization and partial purification of a proteinase from the intestinal smooth muscle of rats fed on protein-free diets are described. 2. It has a mol.wt. of about 33000 and it is stable over a narrow pH range. 3. From its susceptibility to known modifers of proteolytic enzymes, it appears to be a serine proteinase of a trypsin-like nature. Active-site titration with soya-bean trypsin inhibitor shows that the concentration of proteinase was about 3 microgram/g wet wt. of intestinal smooth muscle. However, the muscle proteinase demonstrates a marked ability for inactivating enzymes in their native conformation at neutral pH. It is about 100 times more efficient than pancreatic trypsin when the inactivating activities are compared on an approximately equimolar basis. 4. Inactivation of the substrate enzymes is accompanied by limited proteolysis, as demonstrated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. 5. An endogenous inhibitor was separated from the proteinase by fractionation with (NH4)2SO4. 6. Contamination of the muscle tissue by lumen, mucosal or blood proteinases and inhibitors is shown to be unlikely. 7. A role for the neutral trypsin-like proteinase in initiating the degradation of intracellular enzymes is considered.

Renin in the Mouse Kidney Has a Molecular Weight of 40 000

1981 ◽  
Vol 60 (1) ◽  
pp. 41-46 ◽  
Author(s):  
K. Poulsen ◽  
A. H. Nielsen
Keyword(s):  
Molecular Weight ◽  
Enzymatic Activity ◽  
High Molecular Weight ◽  
Enzyme Inhibitors ◽  
Polyacrylamide Gel Electrophoresis ◽  
Limited Proteolysis ◽  
Gel Filtration ◽  
Mouse Kidney ◽  
Antigenic Properties ◽  
Before And After

1. Mouse kidney was homogenized in a mixture of serine-metallo- and thiol-enzyme inhibitors. The homogenate proteins were separated with respect to size and charge by gel filtration, agarose electrophoresis and polyacrylamide-gel electrophoresis. 2. Renin was localized by its enzymatic activity by using the antibody trapping radioimmunoassay for angiotensin I, before and after acid treatment and limited proteolysis. Renin was also localized by its antigenic properties by using antirenin antibodies elicited against pure mouse submaxillary renin. The antibody cross-reacted fully with mouse kidney renin and with high-molecular-weight renin forms in mouse plasma. 3. In the kidney only fully enzymically active 40 000 renin could be detected enzymically and antigenically. No high-molecular-weight renin or inactive renin was demonstrable. 4. Two electrophoretically different renin forms were seen in accordance with renin being a glycoprotein. They were both fully enzymically active with identical specific enzymatic activities. 5. The mouse kidney renin had a specific enzymatic activity identical with that of pure mouse submaxillary renin, being 0.4 Goldblatt unit/μg.

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