scholarly journals N-Terminal sequences of α-crystallin

1969 ◽  
Vol 115 (4) ◽  
pp. 789-796 ◽  
Author(s):  
P. H. Corran ◽  
S. G. Waley
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Lens Protein ◽  
Amino Group ◽  
Tryptic Digest ◽  
Methionine Residue ◽  
Common Precursor ◽  
A Chain

The amino acid sequences at the N-terminal ends of the chains of the lens protein, α-crystallin, were studied. Both the main kinds of chain in bovine α-crystallin (A chains and B chains) have an N-terminal methionine residue, and the amino group is acetylated. Selective purification of the peptides in a tryptic digest of bovine α-crystallin gave a preparation consisting largely of the N-terminal peptide from the A chains, and the sequence of this peptide was elucidated. Subsequently, the N-terminal peptides were prepared from separated A and B chains. The proposed sequences are: A chain, acetyl-Met-Asp-Ile-Ala-Ile-Gln-His-Pro-Trp-Phe-Lys; B chain, acetyl-Met-Asp-Ile-Ala-Ile-His-(Pro,Trp)-Ile-Arg. The similarity between the sequences supports the hypothesis that the A and B chains are derived evolutionarily from a common precursor.

scholarly journals The Fine Structure of the Sensory Epithelium of the Vomeronasal Organ in Suckling Rats

1971 ◽  
Vol 24 (3) ◽  
pp. 765 ◽  
Author(s):  
Jean E Kratzing
Keyword(s):  
Amino Acid ◽  
Gel Filtration ◽  
Vomeronasal Organ ◽  
Sensory Epithelium ◽  
Exchange Chromatography ◽  
Amino Acid Sequences ◽  
Tryptic Digestion ◽  
Tryptic Peptides ◽  
Special Procedure ◽  
A Chain

The amino acid sequence of the a-chain of haemoglobin from M. giganteus has been determined. The soluble peptides formed by tryptic digestion were isolated by gel filtration, ion-exchange chromatography, paper ionophoresis, and chromatography. The amino acid sequences were determined by the "dansyl"Edman procedure. Incomplete hydrolysis of one bond resulted in a large insolublecore peptide containing 40 amino acid residues. The sequence of this peptide was deduced from the sequences of smaller peptides resulting from further digestion with thermolysin and papain. Maleylation of the a-globin before tryptic digestion gave three large fragments which assisted in assigning tryptic peptides to specific areas of the molecule. A special procedure involving maleylation of a chymotryptic digest of globin was used to isolate peptides containing arginine which provided overlap sequences of tryptic peptides

scholarly journals Studies on Monotreme Proteins. V. Amino Acid Sequence of the a-Chain of Haemoglobin From the Platypus, Ornithorhynchus anatinus

1974 ◽  
Vol 27 (6) ◽  
pp. 591 ◽  
Author(s):  
RG Whittaker ◽  
EOP Thompson
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Tryptic Digestion ◽  
Complete Amino Acid Sequence ◽  
Ornithorhynchus Anatinus ◽  
A Chain

Blood from the platypus contained three haemoglobins which were separated by chromatography on DEAE-Sephadex. The major component, Hb-I, was converted to globin and fractionated into the oc-and p-chains by chromatography on eM-cellulose in 8M urea-thiol buffers, and the complete amino acid sequence of the 141 residues of the oc-chain were determined. Peptides derived from the oc-chain by tryptic digestion were isolated by paper ionophoresis and chromatography. The amino acid sequences were determined by the dansyl-Edman procedure or by further digestion with other enzymes.

scholarly journals Haemoglobins of the Shark, Heterodontus Portusjacksoni II. Amino Acid Sequence of the a-Chain

1976 ◽  
Vol 29 (2) ◽  
pp. 73 ◽  
Author(s):  
AR Nash ◽  
WK Fisher ◽  
EOP Thompson
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Paper Chromatography ◽  
Cyanogen Bromide ◽  
Gel Filtration ◽  
Amino Acid Sequences ◽  
Tryptic Digestion ◽  
Amino Terminal ◽  
Core Peptide ◽  
A Chain

The amino acid sequence of the a-chain of the principal haemoglobin from the shark, H. portusjacksoni has been determined. The chain has 148 residues and is acetylated at the amino terminal. The soluble peptides obtained by tryptic and chymotryptic digestion of the protein or its cyanogen bromide fragments were isolated by gel filtration, paper ionophoresis and paper chromatography. The amino acid sequences were determined by the dansyl-Edman procedure. The insoluble 'core' peptide from the tryptic digestion contained 34 residues and required cleavage by several proteases before the sequence was established. Compared with human a-chain there are 88 amino acid differences including the additional seven residues which appear on the amino terminal of the shark chain. There is also one deletion and one insertion. The chain contains no tryptophan but has four cysteinyl residues which is the highest number of such residues recorded for a vertebrate globin.

scholarly journals Isolation, by partial pepsin digestion, of the three collagen-like regions present in subcomponent Clq of the first component of human complement

1976 ◽  
Vol 155 (1) ◽  
pp. 5-17 ◽  
Author(s):  
K B M Reid
Keyword(s):  
Amino Acid ◽  
Sodium Dodecyl Sulphate ◽  
Sequence Data ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Amino Acid Sequences ◽  
Disulphide Bond ◽  
Small Peptides ◽  
Molecular Weights ◽  
A Chain

1. Digestion of human subcomponent C1q with pepsin at pH4.45 for 20h at 37 degrees C fragmented most of the non-collagen-like amino acid sequences in the molecule to small peptides, whereas the entire regions of collagen-like sequence that comprised 38% by weight of the subcomponent C1q were left intact. 2. The collagen-like fraction of the digest was eluted in the void volume of a Sephadex G-200 column, was was showm to be composed of two major fragments when examined by electrophoresis on polyacrylamide gels run in buffers containing sodium dodecyl sulphate. These fragments were separated on CM-cellulose at pH4.9 in buffers containing 7.5M-urea. 3. Human subcomponent C1q on reduction and alkylation yields equimolar amounnts of three chains, which have been designated A, B and C [Reid et al. (1972) Biochem. J. 130, 749-763]. One of the pepsin fragments was shown to be composed of the N-terminal 95 residues of the A chain linked, via residue A4, by a single disulphide bond to a residue in the sequence B2-B6 in the N-terminal 91 residues of the B chain. The second pepsin fragment was shown to be composed of a disulphide-linked dimer of the N-terminal 94 residues of the C chain, the only disulphide bond being located at residue C4.4. The mol. wts. of the unoxidized and oxidized pepsin fragments were estimated from their amino acid compositions to be 20 000 and 18 200 for the A-B and C-C dimers and 11 400, 8800 and 9600 for the collagen-like fragments of the A, B and C chains respectively. Estimation of the molecular weights of the peptic fragments by polyacrylamide-gel electrophoresis run in the presence of sodium dodecyl sulphate gave values that were approx. 50% higher than expected from the amino acid sequence data. This is probably due to the high collagen-like sequence content of these fragments.

scholarly journals Amino acid sequences of peptides from a tryptic digest of a urea-soluble protein fraction (U.S.3) from oxidized wool

1967 ◽  
Vol 102 (3) ◽  
pp. 801-814 ◽  
Author(s):  
M. C. Corfield ◽  
J. C. Fletcher ◽  
A. Robson
Keyword(s):  
Amino Acid ◽  
Cation Exchange ◽  
Protein Fraction ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Paper Electrophoresis ◽  
Amino Acid Sequences ◽  
Tryptic Digest ◽  
Parent Protein ◽  
Wool Proteins

1. A tryptic digest of the protein fraction U.S.3 from oxidized wool has been separated into 32 peptide fractions by cation-exchange resin chromatography. 2. Most of these fractions have been resolved into their component peptides by a combination of the techniques of cation-exchange resin chromatography, paper chromatography and paper electrophoresis. 3. The amino acid compositions of 58 of the peptides in the digest present in the largest amounts have been determined. 4. The amino acid sequences of 38 of these have been completely elucidated and those of six others partially derived. 5. These findings indicate that the parent protein in wool from which the protein fraction U.S.3 is derived has a minimum molecular weight of 74000. 6. The structures of wool proteins are discussed in the light of the peptide sequences determined, and, in particular, of those sequences in fraction U.S.3 that could not be elucidated.

scholarly journals Regulatory mechanisms in immune responses to heterologous insulins. II. Suppressor T cell activation associated with nonresponsiveness in H-2b mice.

1984 ◽  
Vol 160 (4) ◽  
pp. 1012-1026 ◽  
Author(s):  
P E Jensen ◽  
C W Pierce ◽  
J A Kapp
Keyword(s):  
T Cells ◽  
Amino Acid ◽  
T Cell Activation ◽  
Amino Acid Sequences ◽  
Antibody Responses ◽  
Helper T Cells ◽  
Secondary Response ◽  
Suppressor T Cells ◽  
A Chain ◽  
Specific Suppressor T Cells

Murine antibody responses to insulins are controlled by MHC-linked Ir genes. Although mice of the H-2b haplotype do not make antibody in response to pork insulin, we demonstrate in this communication that immunization with pork insulin stimulates radioresistant, Lyt-1+2- helper T cells that are capable of stimulating secondary antibody responses to pork insulin in vitro, but that this activity is masked by radiosensitive, Lyt-1-2+, I-J+ suppressor T cells. The suppressor T cells, present after immunization with pork insulin but not beef insulin, suppress the secondary response to pork but not beef insulin. The amino acid sequences of pork and beef insulins differ only at the A-chain loop; thus, pork insulin-specific suppressor T cells appear to recognize the A-chain loop determinant of pork insulin. The amino acid sequences of mouse and pork insulin are identical in the A-chain loop, which suggests that these suppressor T cells may be self-reactive. If this interpretation is correct, these suppressor T cells could be involved in the maintenance of self-tolerance to insulin. Nevertheless, these data clearly demonstrate that genetically determined nonresponsiveness in H-2b mice is conferred by activation of dominant, insulin-specific suppressor T cells (Ts), rather than by a defect in the stimulation of insulin-specific helper T cells (Th).

scholarly journals Completion of the amino acid sequences of the A and B chains of subcomponent C1q of the first component of human complement

1982 ◽  
Vol 203 (3) ◽  
pp. 559-569 ◽  
Author(s):  
K B M Reid ◽  
J Gagnon ◽  
J Frampton
Keyword(s):  
Amino Acid ◽  
Structure Prediction ◽  
Sequence Data ◽  
Helical Structure ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Human Complement ◽  
Major Site ◽  
A Chain ◽  
Asparagine Residue

The sequences of amino acid residues 109-224 of the A chain, and residues 109-22 of the B chain, of human subcomponent C1q are given. These results, along with previously published sequence data on the N-terminal, collagen-like, regions of the A and B chains [Reid (1979) Biochem. J. 179, 367-371] yield the complete amino acid sequences of the A and B chains of subcomponent C1q. The asparagine residue at position A-124 has been identified as the major site of asparagine-linked carbohydrate in subcomponent C1q. When the sequences of the C-terminal, 135-residue-long, ‘globular’ regions of A and B chains are compared they show 40% homology. The degree of homology over certain stretches of 15-20 residues, within the C-terminal regions, rises up to values of 73%, indicating the presence of strongly conserved structures. Structure prediction studies indicate that both the A and B chain C-terminal regions may adopt a predominantly beta-type structure with apparently little alpha-helical structure.

Amino Acid Sequences of Peptides from the Tryptic Digest of Golfingia gouldii Hemerythrin*

Biochemistry ◽  
1966 ◽  
Vol 5 (12) ◽  
pp. 3783-3796 ◽  
Author(s):  
W. R. Groskopf ◽  
J. W. Holleman ◽  
E. Margoliash ◽  
I. M. Klotz
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Tryptic Digest

scholarly journals The amino acid sequences of erabutoxins, neurotoxic proteins of sea-snake (Laticauda semifasciata) venom

1971 ◽  
Vol 122 (4) ◽  
pp. 453-461 ◽  
Author(s):  
S. Sato ◽  
N. Tamiya
Keyword(s):  
Amino Acid ◽  
Paper Electrophoresis ◽  
Amino Acid Sequences ◽  
Edman Degradation ◽  
Terminal Sequence ◽  
Amino Acid Sequence Analysis ◽  
Sea Snake ◽  
Tryptic Digest ◽  
Laticauda Semifasciata ◽  
Erabutoxin B

1. Erabutoxin b was reduced, S-carboxymethylated and hydrolysed with trypsin. Seven tryptic fragments were isolated by column chromatography and paper electrophoresis. Some of the fragments were further hydrolysed with α-chymotrypsin, pepsin, Nagarse, Proctase A or Proctase B. The amino acid sequences of the fragment peptides were determined by subtractive Edman degradation. 2. From the tryptic digest of reduced, S-carboxymethylated and trifluoroacetylated erabutoxin b two fragments were isolated. From the amino acid composition of the fragments and from the terminal sequence studies on the reduced and S-carboxymethylated erabutoxin b, the sequence of the above seven tryptic fragments was elucidated. 3. The tryptic digestion of reduced and S-carboxymethylated erabutoxin a gave fragments, only one of which was different from the corresponding fragment from erabutoxin b. The amino acid sequence analysis of the fragment peptide showed that the only difference between erabutoxins a and b was that the former had asparagine and the latter had histidine at position 26.

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