scholarly journals Structural studies on bovine γ-crystallin

1971 ◽  
Vol 121 (3) ◽  
pp. 453-459 ◽  
Author(s):  
L. R. Croft ◽  
S. G. Waley
Keyword(s):  
Amino Acid ◽  
Amino Acid Analysis ◽  
Polypeptide Chain ◽  
Amino Acid Sequences ◽  
Performic Acid ◽  
Cysteic Acid ◽  
Cysteine Residues ◽  
Lens Protein ◽  
Structural Studies ◽  
Protein Amino Acid

The amino acid sequences around the cysteine residues in the lens protein, γ-crystallin, were studied. Fraction II of the γ-crystallin from calf lens (Björk, 1964) was used. The protein was oxidized with performic acid and then hydrolysed with trypsin. Six peptides containing cysteic acid were isolated. One of the peptides contained three residues of cysteic acid and the others contained one residue of cysteic acid. We conclude that there are eight unique residues of cysteic acid in the oxidized protein. Amino acid analysis suggests that there are also eight residues of cysteic acid in the molecule, which thus contains only one polypeptide chain.

scholarly journals Amino Acid Sequences Containing Cysteine or Half-Cystine Residues in ß-Glucuronidase

1980 ◽  
Vol 33 (5) ◽  
pp. 513 ◽  
Author(s):  
PH Leighton ◽  
WK Fisher ◽  
KE Moon ◽  
EOP Thompson
Keyword(s):  
Amino Acid ◽  
Amino Acid Analysis ◽  
Amino Acid Sequences ◽  
Sulfhydryl Groups ◽  
Cysteic Acid ◽  
Cysteine Residues

Amino acid analysis of oxidized or reduced and carboxymethylated p-glucuronidase have shown the presence of 24 cysteic acid or S-carboxymethylcysteine residues respectively per mole of the tetrameric enzyme. Titration of sulfhydryl groups gave eight cysteine residues, and by difference 16 half-cystine residues per mole.

scholarly journals The amino acid sequence of cysteic acid-containing peptides from performic acid-oxidized ovotransferrin

1970 ◽  
Vol 116 (3) ◽  
pp. 515-532 ◽  
Author(s):  
T. C. Elleman ◽  
J. Williams
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Performic Acid ◽  
Cysteic Acid ◽  
Cystine Content

1. The half-cystine content of ovotransferrin, measured as cysteic acid, was 31mol/80000g of protein. 2. The amino acid sequences of cysteic acid-containing peptides from performic acid-oxidized ovotransferrin were studied. 3. 34 unique cysteic acid residues were identified. 4. It is concluded that hen ovotransferrin does not consist of two identical halves or subunits.

scholarly journals Selective purification of the thiol peptides of myosin

1968 ◽  
Vol 107 (4) ◽  
pp. 531-548 ◽  
Author(s):  
A G Weeds ◽  
B S Hartley
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Performic Acid ◽  
Cysteic Acid ◽  
Acid Oxidation ◽  
Thiol Groups ◽  
Peptide Maps ◽  
Thiol Peptides

1. A method for selective purification of thiol peptides is described. Thiol groups in a protein are treated with radioactive cystine by disulphide–thiol interchange. The labelled cystine peptides in a digest can then be fractionated for peptide ‘maps’. Performic acid oxidation of paper strips containing the radioactive peptides followed by further ionophoresis yields the purified cysteic acid peptides. 2. The thiol peptides in a peptic digest of cystine-exchanged myosin were purified in this way, and their amino acid sequences were determined. 3. The conclusion that myosin contains at least 16, and probably between 20 and 22, unique thiol sequences indicates that the molecule consists of two chemically equivalent components.

scholarly journals Bile-pigment formation from different leghaemoglobins. Methine-bridge specificity of coupled oxidation

1978 ◽  
Vol 176 (2) ◽  
pp. 359-364 ◽  
Author(s):  
Päivi Lehtovaara ◽  
Ulla Perttilä
Keyword(s):  
Amino Acid ◽  
Polypeptide Chain ◽  
Broad Bean ◽  
Amino Acid Sequences ◽  
Second Step ◽  
Bile Pigment ◽  
Site Specificity ◽  
Amino Acid Residues ◽  
Reaction Step ◽  
Pigment Formation

The coupled oxidation of leghaemoglobins with O2 and ascorbate yielded oxyleghaemoglobin in the first reaction step, and the second step was the degradation of haem characterized by an A675 increase. Leghaemoglobins were degraded to biliverdin isomers specifically, depending on the structure of the protein. The main leghaemoglobin components of Glycine (soya bean) and Phaseolus (kidney bean) were degraded to biliverdin mixtures containing about 50% of the β-form, about 30% of the α-form and about 20% of the δ-isomer, whereas the leghaemoglobin I components of Vicia (broad bean) and Pisum (pea) were degraded almost exclusively to the β-isomer, with traces of the α-isomer. The amino acid sequences of Glycine and Phaseolus leghaemoglobins resemble each other, as do those of Vicia and Pisum. The site specificity of bile-pigment formation from leghaemoglobins can be tentatively explained by specific differences in the amino acid sequences at those regions of the polypeptide chain that are in the vicinity of the appropriate methine bridges. The ligand-binding site in different leghaemoglobins may be outlined on the basis of the present results, supposing that the haem is degraded when a reduction product of haem-bound O2 reacts with a methine bridge of the haem, and that the bridge specificity is regulated by hindering amino acid residues that determine the location of the bound O2. The residue phenylalanine-CD1 appears to be further away from the haem plane or in a markedly more flexible position in leghaemoglobins than in mammalian globins. The haem-bound oxygen atom B, in Fe–O(A)–O(B), seems to be free to rotate in all directions except that of the γ-bridge in Glycine and Phaseolus leghaemoglobins, but its position in Vicia and Pisum leghaemoglobin I might be restricted to the direction of the β-methine bridge.

scholarly journals Structural studies on lamin. Similarities and differences between lamin and intermediate-filament proteins

1986 ◽  
Vol 238 (1) ◽  
pp. 305-308 ◽  
Author(s):  
D A D Parry ◽  
J F Conway ◽  
P M Steinert
Keyword(s):  
Amino Acid ◽  
Coiled Coil ◽  
Amino Acid Sequences ◽  
Ionic Interactions ◽  
Structural Studies ◽  
Intermediate Filament Proteins ◽  
Coiled Coil Domain ◽  
Similarities And Differences ◽  
Almost Continuous

Analysis of the amino acid sequences of lamins A and C has revealed that each chain has an almost continuous heptad-containing coiled-coil domain containing structural regularities in the linear disposition of the acidic and the basic residues. The data suggest that the lamin molecules are two-stranded ropes, that the two chains are parallel to one another and in axial register, and that the molecules aggregate in vivo through periodic ionic interactions. These results indicate that significant changes in stability of the nuclear envelope may be achieved between interphase and mitosis through changes in the degree of phosphorylation of the lamin proteins.

scholarly journals Alignment of Amino Acid and DNA Sequences of Human Proline-rich Proteins

1993 ◽  
Vol 4 (3) ◽  
pp. 287-292 ◽  
Author(s):  
D.L. Kauffman ◽  
P.J. Keller ◽  
A. Bennick ◽  
M. Blum
Keyword(s):  
Amino Acid ◽  
Dna Sequences ◽  
Sequence Data ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Amino Acid Sequences ◽  
Secreted Proteins ◽  
Dna Encoding ◽  
Protein Amino Acid ◽  
Primary Gene

Human proline-rich proteins (PRPs) constitute a complex family of salivary proteins that are encoded by a small number of genes. The primary gene product is cleaved by proteases, thereby giving rise to about 20 secreted proteins. To determine the genes for the secreted PRPs, therefore, it is necessary to obtain sequences of both the secreted proteins and the DNA encoding these proteins. We have sequenced most PRPs from one donor (D.K.) and aligned the protein sequences with available DNA sequences from unrelated individuals. Partial sequence data have now been obtained for an additional PRP from D.K. named II-1. This protein was purified from parotid saliva by gel filtration and ion-exchange chromatography. Peptides were obtained by cleavage with trypsin, clostripain, and N-bromosuccinimide, followed by column chromatography. The peptides were sequenced on a gas-phase protein sequenator. Overlapping peptide sequences were obtained for most of II-1 and aligned with translated DNA sequences. The best fit was obtained with clones containing sequences for the allele PRB4" (Lyons et al., 1988). However, there was not complete identity of the protein amino acid sequence and the DNA-derived sequences, indicating that II-1 is not encoded by PRB4". Other PRPs isolated from D.K. also fail to conform to any DNA structure so far reported. This shows the need to obtain amino acid sequences and corresponding DNA sequences from the same person to assign genes for the PRPs and to determine the location of the postribosomal cleavage points in the primary translation product.

scholarly journals Disulphide bridges of the heavy chain of human immunoglobulin G2

1971 ◽  
Vol 121 (2) ◽  
pp. 217-225 ◽  
Author(s):  
C. Milstein ◽  
B. Frangione
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Heavy Chain ◽  
Amino Acid Sequences ◽  
Cysteic Acid ◽  
Partial Reduction ◽  
Variable Part ◽  
One Dimensional ◽  
Heavy Chains ◽  
Dimensional Electrophoresis

Amino acid sequences around the disulphide bridges of the heavy chain of an immunoglobulin of the γ2 subclass have been studied. The protein was digested with pepsin and the digest fractionated by Sephadex. Screening of the eluate by one-dimensional electrophoresis of oxidized and unoxidized samples was used as an assay and pools of fractions were prepared. Identification by diagonal electrophoresis of several inter- and intra-chain disulphide bridges was done on the pooled fractions. The inter-heavy-chain bridged peptide included four cystine residues. Comparison with proteins of other human subclasses indicated that the intrachain bridges identified are the bridges of the invariable section of γ2 heavy chains. The amino acid sequence of one cysteic acid peptide that may have been derived from the variable part of the molecule was determined. Partial reduction followed by carboxymethylation with radioactive iodoacetate of two proteins of the γ2 class showed a number of labelled peptides that could be identified as being related to the inter-chain bonded cystine residues.

scholarly journals Amino acid sequences around the cysteine residues of rabbit muscle triose phosphate isomerase

1971 ◽  
Vol 122 (2) ◽  
pp. 209-218 ◽  
Author(s):  
Janet C. Miller ◽  
S. G. Waley
Keyword(s):  
Amino Acid ◽  
Cyanogen Bromide ◽  
Triose Phosphate Isomerase ◽  
Amino Acid Sequences ◽  
Cysteine Residues ◽  
Rabbit Muscle ◽  
Amino Acid Residues ◽  
Triose Phosphate ◽  
Methionine Residues ◽  
Polypeptide Chains

1. The nature of the subunits in rabbit muscle triose phosphate isomerase has been investigated. 2. Amino acid analyses show that there are five cysteine residues and two methionine residues/subunit. 3. The amino acid sequences around the cysteine residues have been determined; these account for about 75 residues. 4. Cleavage at the methionine residues with cyanogen bromide gave three fragments. 5. These results show that the subunits correspond to polypeptide chains, containing about 230 amino acid residues. The chains in triose phosphate isomerase seem to be shorter than those of other glycolytic enzymes.

Cysteine Sequences of Rabbit Skeletal Tropomyosin

1972 ◽  
Vol 50 (3) ◽  
pp. 330-343 ◽  
Author(s):  
R. S. Hodges ◽  
L. B. Smillie
Keyword(s):  
Amino Acid ◽  
Acid Hydrolysis ◽  
Coiled Coil ◽  
Iodoacetic Acid ◽  
Amino Acid Sequences ◽  
Cysteic Acid ◽  
Chain Packing ◽  
Hydrophobic Residues ◽  
Coil Structure ◽  
Cysteine Content

Amino acid analyses of tropomyosin have shown three cysteine residues per mole (M.W. 70 000) of tropomyosin. The cysteine content was determined by cysteic acid determinations, incorporation of 14C-labelled iodoacetic acid into the protein, and the analysis of S-carboxymethylcysteine after acid hydrolysis. The isolation of three unique cysteinyl peptides is incompatible with a homogeneous tropomyosin preparation of two chemically identical subunits. The amino acid sequences reported in this study indicate a regular repeat of hydrophobic residues as required by the inter-chain packing of a coiled-coil structure.

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