scholarly journals The purification and properties of the second component of human complement

1978 ◽  
Vol 171 (1) ◽  
pp. 99-107 ◽  
Author(s):  
M A Kerr ◽  
R R Porter
Keyword(s):  
Amino Acid ◽  
Polypeptide Chain ◽  
Alternative Pathway ◽  
Polyacrylamide Gel Electrophoresis ◽  
Complement Factor ◽  
Human Complement ◽  
Terminal Amino Acid ◽  
Factor B ◽  
Antigenic Properties ◽  
Terminal Amino

The second component of human complement (C2) was purified by a combination of euglobulin precipitation, ion-exchange chromatography, (NH4)2SO4 precipitation and affinity chromatography. The final product was homogeneous by the criterion of polyacrylamide-gel electrophoresis and represents a purification of about 4000-fold from serum with 15-20% yield. Component C2 comprises a single carbohydrate-containing polypeptide chain, with an apparent mol.wt. of 102000; alanine is the N-terminal amino acid. The molecule is rapidly cleaved by activated subcomponent C1s with the loss of haemolytic activity to yield two fragments with apparent mol.wts. of 74000 and 34000. These fragments are not linked by disulphide bonds and can be easily separated. A second protein isolated during the purification of component C2 was identified by its haemolytic and antigenic properties as complement Factor B, the protein serving an analogous function to component C2 in the alternative pathway. The protein, which is also a single carbohydrate-containing polypeptide chain, has an apparent mol.wt. of 95000 and threonine as N-terminal amino acid. The amino acid analyses of component C2 and Factor B are compared.

PURIFICATION AND PARTIAL CHEMICAL CHARACTERIZATION OF SHEEP NEUROPHYSIN

1973 ◽  
Vol 74 (2) ◽  
pp. 226-236 ◽  
Author(s):  
Michel Chrétien ◽  
Claude Gilardeau
Keyword(s):  
Amino Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Chemical Characterization ◽  
Terminal Amino Acid ◽  
Amino Acid Determination ◽  
Pituitary Glands ◽  
Terminal Amino ◽  
Partial Chemical ◽  
Acid Determination

ABSTRACT A protein isolated from ovine pituitary glands has been purified, and its homogeneity assessed by NH2- and COOH-terminal amino acid determination, ultracentrifugation studies, and polyacrylamide gel electrophoresis after carboxymethylation. Its chemical and immunochemical properties are closely similar to those of beef and pork neurophysins, less similar to those of human neurophysins. It contains no tryptophan (like other neurophysins) or histidine (like all except bovine neurophysin-I and human neurophysins). It has alanine at the NH2-terminus and valine at the COOH-terminus. Its amino acid composition is similar to, but not identical with those of porcine and bovine neurophysins.

scholarly journals Factor D̄ of the alternative pathway of human complement. Purification, alignment and N-terminal amino acid sequences of the major cyanogen bromide fragments, and localization of the serine residue at the active site

1980 ◽  
Vol 187 (3) ◽  
pp. 863-874 ◽  
Author(s):  
D M Johnson ◽  
J Gagnon ◽  
K B Reid
Keyword(s):  
Amino Acid ◽  
Sequence Analysis ◽  
Amino Acid Sequence ◽  
Alternative Pathway ◽  
Amino Acid Sequences ◽  
Serine Residue ◽  
Amino Acid Sequence Analysis ◽  
Terminal Amino Acid ◽  
Terminal Amino ◽  
Terminal Amino Acid Sequence

The serine esterase factor D of the complement system was purified from outdated human plasma with a yield of 20% of the initial haemolytic activity found in serum. This represented an approx. 60 000-fold purification. The final product was homogeneous as judged by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis (with an apparent mol.wt. of 24 000), its migration as a single component in a variety of fractionation procedures based on size and charge, and its N-terminal amino-acid-sequence analysis. The N-terminal amino acid sequence of the first 36 residues of the intact molecule was found to be homologous with the N-terminal amino acid sequences of the catalytic chains of other serine esterases. Factor D showed an especially strong homology (greater than 60% identity) with rat ‘group-specific protease’ [Woodbury, Katunuma, Kobayashi, Titani, & Neurath (1978) Biochemistry 17, 811-819] over the first 16 amino acid residues. This similarity is of interest since it is considered that both enzymes may be synthesized in their active, rather than zymogen, forms. The three major CNBr fragments of factor D, which had apparent mol.wts. of 15 800, 6600 and 1700, were purified and then aligned by N-terminal amino acid sequence analysis and amino acid analysis. By using factor D labelled with di-[1,3-14C]isopropylphosphofluoridate it was shown that the CNBr fragment of apparent mol.wt. 6600, which is located in the C-terminal region of factor D, contained the active serine residue. The amino acid sequence around this residue was determined.

Existence of Common Antigenic Determinants in the Aα, Bβ and γ Chains of Some Mammalian Fibrinogens.

1979 ◽  
Author(s):  
C.S. Cierniewski
Keyword(s):  
Amino Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel ◽  
Antigenic Determinants ◽  
Terminal Amino Acid ◽  
Human Fibrinogen ◽  
Passive Hemagglutination ◽  
Terminal Amino ◽  
Polypeptide Chains ◽  
Fibrinogen Molecule

Polypeptide chains Aα, Bβ and γ of porcine fibrinogen were isolated by preparative SDS polyacrylamide gel electrophoresis. Their purity was estimated by electrophoresis in polyacrylamide gel, amino acid composition and N-terminal amino acid analyses. Antisera to the pig polypeptide chains were produced in rabbits and they were employed in immunological comparative studies of porcine, bovine, human and duck fibrinogens. Antisera to the pig Aα chain showed in gel immunodiffusion and passive hemagglutination a strong cross-reaction with porcine, bovine and human fibrinogens. Antisera to the pig βB and γ chains cross-reacted only with porcine and bovine fibrinogens but they did not recognize human fibrinogen, The reaction of antiγ antisera was detectable only by passive hemagglutination test. In all cases antigenic similarity of the analyzed fibrinogens was mainly related to antigenic determinants of the Aα, Bβ and γ chains exposed on the intact fibrinogen molecule. None of analyzed antisera reacted with duck fibrinogen.

Cl̄r and Cl̄s subcomponents of human complement: Two serine proteinases lacking the ‘histidine-loop’ disulphide bridge

1981 ◽  
Vol 1 (10) ◽  
pp. 779-784 ◽  
Author(s):  
Gerard J. Arlaud ◽  
Jean Gagnon
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Histidine Residue ◽  
Serine Proteinases ◽  
Human Complement ◽  
Disulphide Bridge ◽  
Terminal Amino Acid ◽  
Relay System ◽  
Terminal Amino ◽  
Terminal Amino Acid Sequence

The N-terminal amino acid sequence of human Cl̄s b chain has been extended to 52 residues. The histidine residue involved in the charge-relay system is located at position 38, whereas the ‘histidine-loop’ disulphide bridge is missing. So far, human complement subcomponents Cl̄s are the only known mammalian serine proteinases lacking this disulphide bridge.

scholarly journals The principal site of glycation of human complement factor B

1991 ◽  
Vol 274 (2) ◽  
pp. 473-480 ◽  
Author(s):  
M A Niemann ◽  
A S Bhown ◽  
E J Miller
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Sequence Data ◽  
Complement Factor ◽  
Human Complement ◽  
Factor B ◽  
Complement Factor B ◽  
Functional Regions ◽  
High Concentrations

Accumulating amino acid sequence data have made it increasingly evident that many essential complement proteins have potentially modifiable lysine residues in putative critical functional regions. Evidence is now presented that glucose is covalently attached to lysine-266 of purified human complement Factor B as a result of glycation. Purified B was treated with NaB3H4, which reduces such bound glucose to a mixture of radiolabelled hexitols. Amino acid analysis revealed the expected radiolabelled hexitol-lysine epimers. In addition, fluorography of dried gels resolving the major high-molecular-mass h.p.l.c.-fractionated CNBr-cleavage peptides of NaB3H4-reduced B indicated that this radioactivity was specifically associated with the 15 kDa fragment derived from the N-terminal region of fragment Bb. Amino acid sequence analysis suggested that the C-terminal lysine (residue 266 of B) of the N-terminal Lys-Lys doublet of this peptide is preferentially modified. If such glycation can subsequently be shown to occur in vivo, then perhaps this modification might also be found to affect the functional activity of B and offer a potential explanation for some of the immunopathological complications of diseases exposing key plasma proteins, such as this active-site-containing proteinase of the multimeric alternative-complement-pathway C3/C5 convertases, to long-term high concentrations of glucose, such as the decreased resistance to infection and impaired chemotaxis and phagocytosis characteristic of diabetes.

scholarly journals Amino acid sequence of the Bb fragment from human complement Factor B. Alignment of the cyanogen bromide-cleavage peptides

1983 ◽  
Vol 209 (1) ◽  
pp. 51-60 ◽  
Author(s):  
J Gagnon ◽  
D L Christie
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Human Factor ◽  
Alternative Pathway ◽  
Amino Acid Sequences ◽  
Complement Factor ◽  
Factor B ◽  
Arginine Residues ◽  
Alternative Pathway Of Complement ◽  
Cnbr Cleavage

The alignment of all the CNBr-cleavage peptides of fragment Bb from human Factor B (a component of the alternative pathway of complement) was determined. This was derived from cleavage of the fragment Bb at arginine residues by using trypsin and clostripain. Details of the isolation and amino acid sequences of these peptides are given. Together with previously published N-terminal sequences of the CNBr-cleavage peptides [Christie & Gagnon (1982) Biochem. J. 201, 555-567], this provides the amino acid sequence of the N-terminal half of fragment Bb.

scholarly journals The overexpression and complete amino acid sequence of Escherichia coli 3-dehydroquinase

1986 ◽  
Vol 238 (2) ◽  
pp. 475-483 ◽  
Author(s):  
K Duncan ◽  
S Chaudhuri ◽  
M S Campbell ◽  
J R Coggins
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Nucleotide Sequence ◽  
Amino Acid Sequence ◽  
Polypeptide Chain ◽  
Amino Acid Residues ◽  
Transcript Mapping ◽  
Terminal Amino Acid ◽  
Terminal Amino ◽  
Terminal Amino Acid Sequence

The enzyme 3-dehydroquinase was purified in milligram quantities from an overproducing strain of Escherichia coli. The amino acid sequence was deduced from the nucleotide sequence of the aroD gene and confirmed by determining the amino acid composition of the overproduced enzyme and its N-terminal amino acid sequence. The complete polypeptide chain consists of 240 amino acid residues and has a calculated subunit Mr of 26,377. Transcript mapping revealed that aroD is a typical monocistronic gene.

scholarly journals Amino acid sequence of the N-terminal 108 amino acid residues of the B chain of subcomponent C1q of the first component of human complement

1978 ◽  
Vol 173 (3) ◽  
pp. 863-868 ◽  
Author(s):  
K B Reid ◽  
E O Thompson
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Amino Acid Sequence ◽  
Disulphide Bond ◽  
Amino Acid Residues ◽  
Human Complement ◽  
Terminal Amino Acid ◽  
Exact Position ◽  
Terminal Amino

The amino acid sequence of the N-terminal 108 residues of the B chain of subcomponent C1q of the first component of human complement was determined. The B chain has a blocked N-terminal amino acid, which was judged to be 5-oxopyrrolidine-2-carboxylic acid. A collagen-like region of 84 residues was found, which started at position B-6, and all of the six hydroxylysine residues and 12 hydroxyproline residues present in the chain were found in this region. Four of the six hydroxylysine residues may be glycosylated. The repeating nature of the collagen-like region is broken at position B-9, where alanine is found in a position where glycine would be expected. The exact position of the interchain disulphide bond joining the A and B chains of human subcomponent C1q was shown to be between residues A4 and B4.

scholarly journals Subcellular Localization of the Intracellular Survival-Enhancing Eis Protein of Mycobacterium tuberculosis

2001 ◽  
Vol 69 (7) ◽  
pp. 4295-4302 ◽  
Author(s):  
John L. Dahl ◽  
Jun Wei ◽  
James W. Moulder ◽  
Suman Laal ◽  
Richard L. Friedman
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Amino Acid ◽  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Intracellular Survival ◽  
Terminal Amino Acid ◽  
Terminal Amino

ABSTRACT Mycobacterium tuberculosis is a facultative intracellular pathogen that has evolved the ability to survive and multiply within human macrophages. It is not clear how M. tuberculosis avoids the destructive action of macrophages, but this ability is fundamental in the pathogenicity of tuberculosis. A gene previously identified in M. tuberculosis, designatedeis, was found to enhance intracellular survival ofMycobacterium smegmatis in the human macrophage-like cell line U-937 (J. Wei et al., J. Bacteriol. 182:377–384, 2000). Wheneis was introduced into M. smegmatis on a multicopy vector, sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the appearance of a unique 42-kDa protein band corresponding to the predicted molecular weight of the eisgene product. This band was electroeluted from the gel with a purity of >90% and subjected to N-terminal amino acid sequencing, which demonstrated that the 42-kDa band was indeed the protein product ofeis. The Eis protein produced by M. tuberculosis H37Ra had an identical N-terminal amino acid sequence. A synthetic polypeptide corresponding to a carboxyl-terminal region of the deduced eis protein sequence was used to generate affinity-purified rabbit polyclonal antibodies that reacted with the 42-kDa protein in Western blot analysis. Hydropathy profile analysis showed the Eis protein to be predominantly hydrophilic with a potential hydrophobic amino terminus. Phase separation of M. tuberculosis H37Ra lysates by the nonionic detergent Triton X-114 revealed the Eis protein in both the aqueous and detergent phases. After fractionation of M. tuberculosis by differential centrifugation, Eis protein appeared mainly in the cytoplasmic fraction but also in the membrane, cell wall, and culture supernatant fractions as well. Forty percent of the sera from pulmonary tuberculosis patients tested for anti-Eis antibody gave positive reactions in Western blot analysis. Although the function of Eis remains unknown, evidence presented here suggests it associates with the cell surface and is released into the culture medium. It is produced during human tuberculosis infection and therefore may be an important M. tuberculosis immunogen.

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