scholarly journals The amino acid sequence of protein SCMK-B2C from the high-sulphur fraction of wool keratin

1972 ◽  
Vol 128 (5) ◽  
pp. 1229-1239 ◽  
Author(s):  
T. C. Elleman
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Wool Fibre ◽  
Amino Acid Residues ◽  
C Terminus ◽  
Unusual Distribution ◽  
Mechanical And Physical Properties ◽  
N Terminus ◽  
Fibre Matrix ◽  
Wool Keratin

1. The amino acid sequence of a protein from the reduced and carboxymethylated high-sulphur fraction of wool has been determined. 2. The sequence of this S-carboxymethylkerateine (SCMK-B2C) of 151 amino acid residues displays much internal homology and an unusual residue distribution. Thus a ten-residue sequence occurs four times near the N-terminus and five times near the C-terminus with few changes. These regions contain much of the molecule's half-cystine, whereas between them there is a region of 19 residues that are mainly small and devoid of cystine and proline. 3. Certain models of the wool fibre based on its mechanical and physical properties propose a matrix of small compact globular units linked together to form beaded chains. The unusual distribution of the component residues of protein SCMK-B2C suggests structures in the wool-fibre matrix compatible with certain features of the proposed models.

scholarly journals Differentiation of propeptide residues regulating the compartmentalization, maturation and activity of the broad-range phospholipase C of Listeria monocytogenes

2010 ◽  
Vol 432 (3) ◽  
pp. 557-566 ◽  
Author(s):  
Emily R. Slepkov ◽  
Alan Pavinski Bitar ◽  
Hélène Marquis
Keyword(s):  
Cell Wall ◽  
Listeria Monocytogenes ◽  
Amino Acid ◽  
Enzymatic Activity ◽  
Phospholipase C ◽  
Bacterial Pathogen ◽  
Amino Acid Residues ◽  
C Terminus ◽  
N Terminus ◽  
Vacuolar Acidification

The intracellular bacterial pathogen Listeria monocytogenes secretes a broad-range phospholipase C enzyme called PC-PLC (phosphatidylcholine phospholipase C) whose compartmentalization and enzymatic activity is regulated by a 24-amino-acid propeptide (Cys28–Ser51). During intracytosolic multiplication, bacteria accumulate the proform of PC-PLC at their membrane–cell-wall interface, whereas during cell-to-cell spread vacuolar acidification leads to maturation and rapid translocation of PC-PLC across the cell wall in a manner that is dependent on Mpl, the metalloprotease of Listeria. In the present study, we generated a series of propeptide mutants to determine the minimal requirement to prevent PC-PLC enzymatic activity and to identify residues regulating compartmentalization and maturation. We found that a single residue at position P1 (Ser51) of the cleavage site is sufficient to prevent enzymatic activity, which is consistent with P1′ (Trp52) being located within the active-site pocket. We observed that mutants with deletions at the N-terminus, but not the C-terminus, of the propeptide are translocated across the cell wall more effectively than wild-type PC-PLC at a physiological pH, and that individual amino acid residues within the N-terminus influence Mpl-mediated maturation of PC-PLC at acidic pH. However, deletion of more than 75% of the propeptide was required to completely prevent Mpl-mediated maturation of PC-PLC. These results indicate that the N-terminus of the propeptide regulates PC-PLC compartmentalization and that specific residues within the N-terminus influence the ability of Mpl to mediate PC-PLC maturation, although a six-residue propeptide is sufficient for Mpl to mediate PC-PLC maturation.

scholarly journals Determination of the immunogenic region in the LipL32 protein of Leptospira

2018 ◽  
pp. 27-33
Author(s):  
Mohammad Iskandar Jumat ◽  
Kenneth Francis Rodrigues ◽  
Azlyna Laribe ◽  
Rashidah Mohammad ◽  
Timothy William ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
High Specificity ◽  
Full Length ◽  
Immunogenic Region ◽  
C Terminus ◽  
Initial Symptoms ◽  
N Terminus ◽  
Low Sensitivity

Leptospirosis is a zoonotic disease caused by the pathogenic species of Leptospira. The initial symptoms include fever, myalgia, nausea, skin rash, chills, and headache, which can be misdiagnosed. LipL32 is the highly conserved and abundant outer membrane protein (OMP) of Leptospira, which is used as an antigen in serodiagnostic assays. We used three in silico methods to predict the immunodominant regions in the full-length LipL32 protein. We identified three regions, namely the N-terminus (NrLipL32, amino acid sequence 20th-120th), intermediate (amino acid sequence 120th-150th), and C-terminus (CrLipL32, amino acid sequence 160th-260th) regions. The full-length protein and two larger fragments were cloned into the pET22b plasmid and expressed in Escherichia coli BL21 (DE3). The purified proteins were used as antigens in an ELISA to detect Leptospira-specific antibodies. The CrLipL32 ELISA showed the highest sensitivity for IgM (73.3%) and IgG (65%), followed by the full-length rLipL32 ELISA (IgM 68% and IgG 60%). The full-length rLipL32 ELISA showed high specificity (IgM 85% and IgG 75%), followed by the NrLipL32 ELISA (IgM 75% and IgG 60%). The intermediate fragment showed very low sensitivity (IgM 17% and IgG 2%). The sensitivity of the rLipL32 ELISA could be enhanced by adding other OMPs of Leptospira.

scholarly journals Partial amino acid sequence of rat pre-prolactin

1977 ◽  
Vol 161 (1) ◽  
pp. 189-192 ◽  
Author(s):  
R A Maurer ◽  
J Gorski ◽  
D J McKean
Keyword(s):  
Amino Acid ◽  
Sequence Analysis ◽  
Amino Acid Sequence ◽  
Cysteine Residue ◽  
Amino Acid Residues ◽  
Partial Amino Acid Sequence ◽  
Considerable Similarity ◽  
Rat Pituitary ◽  
N Terminus ◽  
Methionine Residues

Rat pituitary mRNA was used to direct the cell-free synthesis of pre-prolactin labelled with [4,5-3H]leucine and either [35S] methioninc or [35S] cystine. Sequence analysis of the labelled protein indicates that pre-prolactin has 29 amino acid residues joined to the N-terminus of the prolactin sequence. Leucine residues were found at positions 13, 14, 15, 16, 21 and 22, methionine residues at positions 1, 17 and 18, and a cysteine residue at position 24 of the precursor sequence, and this partial sequence shows considerable similarity with other precursors that have been sequenced.

scholarly journals Amino acid-sequence variability at the N-terminal extra piece of mouse immunoglobulin light-chain precursors of the same and different subgroups

1976 ◽  
Vol 157 (1) ◽  
pp. 145-151 ◽  
Author(s):  
Y Burstein ◽  
I Schechter
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Light Chain ◽  
Variable Region ◽  
Amino Acid Residues ◽  
Free System ◽  
Methionine Residue ◽  
N Terminus ◽  
Mouse Myeloma

The proteins programmed in the wheat-germ cell-free system by the mRNA coding for the MOPC-63 mouse myeloma L (light) chain were labelled with six radioactive amino acids: [35S]methionine, [4,5-3H]leucine, [3,4-3H]proline, [3-3H]serine, [4,5-3H]isoleucine or [2,3-3H]alanine. Amino acid-sequence analyses showed that over 90% of the total cell-free product was one homogeneous protein, which corresponds to the MOPC-63 L-chain precursor. In this precursor an extra piece, 20 amino acid residues in length, precedes the N-terminus of the mature L chain. The extra piece contains one methionine residue at the N-terminus, six leucine residues, which are clustered in two triplets at positions 6, 7, 8 and 11, 12, 13, one proline residue at position 16, and one serine residue at position 18. The closely gathered leucine residues, as well as their abundance (30%), suggest that the extra-piece moiety is hydrophobic. In the precursors, the extra piece is coupled to the variable region of the L chain. Partial sequences of precursors of L chains of the same and different subgroups that were labelled with the above six radioactive amino acids indicate that the extra piece is part of the variable region. Thus the precursors of MOPC-63 and MOPC-321 L chains, which are of the same subgroup, have extra pieces of identical size (20 residues), and so far their partial sequences are also identical (see above). On the other hand, in the precursor of MOPC-41 L chain, which is of a different subgroup, the extra piece is 22 residues in length. Further, the sequence of the MOPC-41 extra piece differs in at least ten positions from sequences of the extra pieces of the precursors of MOPC-63 and MOPC-321 L chains.

scholarly journals Isolation, properties and amino acid sequence of a long-chain neurotoxin, Acanthophis antarcticus b, from the venom of an Australian snake (the common death adder, Acanthophis antarcticus)

1981 ◽  
Vol 193 (3) ◽  
pp. 899-906 ◽  
Author(s):  
H S Kim ◽  
N Tamiya
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Intramuscular Injection ◽  
Amino Acid Residues ◽  
Methionine Residue ◽  
N Terminus ◽  
The Common ◽  
Ld50 Value ◽  
Almost All ◽  
Long Chain

The venom of an Australian elapid snake, the common death adder (Acanthophis antarcticus), was chromatographed on a CM-cellulose CM52 column. One of the neurotoxic components, Acanthophis antarcticus b (toxin Aa b) was isolated in about 9.4% (A280) yield. The complete amino acid sequence of toxin Aa b was elucidated. Toxin Aa b is composed of 73 amino acid residues, with ten half-cystine residues, and has a formula weight of 8135. Toxin Aa b has no histidine or methionine residue in its sequence. The amino acid sequence of toxin Aa b is homologous with those of other neurotoxins with known sequences, although it is novel in having a valine residue at its N-terminus and an arginine residue at position-23, where a lysine residue is found in almost all the so-far-known neurotoxins. Irrespective of the latter replacement, the toxin Aa b is fully active, with an LD50 value (in mice) of 0.13 microgram/g body weight on intramuscular injection.

Amino Acid Sequence Studies of Horseradish Peroxidase. II. Thermolytic Peptides

1972 ◽  
Vol 50 (1) ◽  
pp. 63-90 ◽  
Author(s):  
K. G. Welinder ◽  
L. B. Smillie
Keyword(s):  
Amino Acid ◽  
Horseradish Peroxidase ◽  
Amino Acid Sequence ◽  
Cation Exchanger ◽  
Paper Electrophoresis ◽  
Tryptophan Residue ◽  
Amino Acid Residues ◽  
Disulfide Bridges ◽  
Serine Residue ◽  
C Terminus

Horseradish peroxidase (HRP) was digested with thermolysin. On fractionation on Sephadex G-25, Fine Chromobeads type P (Dowex 50 type resin) and by high-voltage paper electrophoresis, we isolated about 120 thermolytic peptides. Some experimentation on the composition of the pyridine acetate gradient, used for elution of the cation exchanger, is reported. All peptides were characterized with respect to amino acid composition, N-terminal residue, and pH 6.5 mobility. Unknown peptides or peptides not corresponding unambiguously to previously established tryptic sequences were subjected to dansyl-Edman analysis. Thermolytic peptides accounting for all tryptic sequences except a dipeptide and a tripeptide, and unique thermolytic sequences accounting for about 100 amino acid residues, were obtained. Nine convincing and several indicative overlaps were established for known tryptic sequences. The sequences around all four disulfide bridges, the three histidine residues, and the only tryptophan residue have been elucidated. Eight sites of carbohydrate attachment have been identified. For seven of these sites we have evidence for attachment to asparagine, and for six of the sites the carbohydrate-bound asparagine was found in the well-known sequences Asn–X–Ser/Thr. The remaining two sequences, though incomplete, are compatible with this pattern. Tentatively we suggest a pyrrolidone carboxyl N-terminal for HRP. The specificity of trypsin implicates a sequence found in two varieties, differing only by a C-terminal serine residue at the C-terminus of HRP. A discussion of the possible complications of the acidic heme extraction on the results obtained is included.

scholarly journals The amino acid sequence of troponin I from rabbit skeletal muscle

1975 ◽  
Vol 149 (2) ◽  
pp. 493-496 ◽  
Author(s):  
J M Wilkinson ◽  
R J A. Grand
Keyword(s):  
Skeletal Muscle ◽  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Cyanogen Bromide ◽  
Troponin I ◽  
Rabbit Skeletal Muscle ◽  
British Library ◽  
Amino Acid Residues ◽  
N Terminus

The complete amino acid sequence of rabbit skeletal muscle troponin I was determined by the isolation of the cyanogen bromide fragments and the tryptic methionine-containing peptides. Troponin I contains 179 amino acid residues and has a molecular weight of 20864. Its N-terminus is acetylated. Detailed evidence on which the sequence is based has been deposited as Supplementary Publication SUP 50055 (23 pages) at the British Library (Lending Division), Boston Spa, Wetherby, West Yorkshire LS23 7QB, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1975) 145, 5.

scholarly journals Influence of N-terminal acetylation and C-terminal proteolysis on the analgesic activity of β-endorphin

1980 ◽  
Vol 189 (3) ◽  
pp. 501-506 ◽  
Author(s):  
J F W Deakin ◽  
J O Doströvsky ◽  
D G Smyth
Keyword(s):  
Amino Acid ◽  
Opiate Receptors ◽  
Acetyl Derivative ◽  
Amino Acid Residues ◽  
Duration Of Action ◽  
Beta Endorphin ◽  
C Terminus ◽  
N Terminus ◽  
Specific Affinity

Removal of one, two and four amino-acid residues from the C-terminus of beta-endorphin (‘lipotropin C-Fragment’, lipotropin residues 61–91) led to the formation of peptides with progressively decreased analgesic potency; there was no change in the persistence of the analgesic effects. The four C-terminal residues are thus important for the activity of beta-endorphin, but not for the duration of action. Removal of eight amino-acid residues from the N-terminus provided a peptide that had no specific affinity for brain opiate receptors in vitro and was devoid of analgesic properties. The N-terminal sequence of beta-endorphin is therefore necessary for the production of analgesia, whereas the C-terminal residues confer potency. The N alpha-acetyl form of beta-endorphin had no specific affinity for brain opiate receptors in vitro and possessed no significant analgesic properties. Since lipotropin C'-Fragment (lipotropin residues 61–87) and the N alpha-acetyl derivative of beta-endorphin occur naturally in brain and pituitary and are only weakly active or inactive as opiates, it is suggested that proteolysis at the C-terminus and acetylation of the N-terminus of beta-endorphin may constitute physiological mechanisms for inactivation of this potent analgesic peptide.

scholarly journals The amino acid sequence of ferredoxin from Brassica napus (rape)

1980 ◽  
Vol 185 (1) ◽  
pp. 239-243 ◽  
Author(s):  
I Takruri ◽  
D Boulter
Keyword(s):  
Amino Acid ◽  
Brassica Napus ◽  
Amino Acid Sequence ◽  
Polypeptide Chain ◽  
Amino Acid Residues ◽  
Plant Type ◽  
Single Polypeptide Chain ◽  
N Terminus ◽  
Single Polypeptide

The amino acid sequence of the ferredoxin of Brassica napus was determined by using a Beckman 890C sequencer in combination with the characterization of peptides obtained by tryptic and chymotryptic digestion of the protein; some peptides were subdigested with thermolysin. The molecule consists of a single polypeptide chain of 96 amino acid residues and has an unblocked N-terminus. The primary structure shows considerable similarity with other plant-type ferredoxins.

scholarly journals The amino acid sequence of protein SCMK-B2A from the high-sulphur fraction of wool keratin

1972 ◽  
Vol 130 (3) ◽  
pp. 833-845 ◽  
Author(s):  
T. C. Elleman
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Residues ◽  
High Degree ◽  
Wool Keratin

1. The amino acid sequence of protein SCMK-B2A, a reduced and S-carboxymethylated protein from the high-sulphur fraction of wool, has been determined. 2. This protein of 171 amino acid residues displays both a high degree of internal homology and extensive external homology with other members of the SCMK-B2 group of proteins. 3. Evidence is presented which suggests that the SCMK-B2 group of proteins are produced by separate non-allelic genes.

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