scholarly journals Studies on the structure of sphingomyelinase. Amino acid composition and heterogeneity on isoelectric focusing

1983 ◽  
Vol 209 (2) ◽  
pp. 291-297 ◽  
Author(s):  
C S Jones ◽  
P Shankaran ◽  
D J Davidson ◽  
A Poulos ◽  
J W Callahan
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Isoelectric Focusing ◽  
Protein Profile ◽  
Minor Component ◽  
Intact Protein ◽  
Amino Acid Residues ◽  
Apparent Homogeneity ◽  
A Minor

Sphingomyelinase, purified to apparent homogeneity from human placenta, is an acidic protein, as judged from its amino acid composition and by isoelectric focusing of the carboxymethylated protein. The amino acid composition is characterized by an approximately equal content of hydrophobic and polar amino acid residues. The reduced-alkylated polypeptides were separated into two groups. Most of the polypeptides were heterogeneous with pI values of 4.4-5.0, but an additional more minor component was observed at pI 5.4. Liquid isoelectric focusing resolved the purified enzyme into a single major component (pI 4.7-4.8), a minor component (pI 5.0-5.4) and a plateau region of activity (pI 6-7). On thin-layer isoelectric focusing, the protein profile obtained from each of these regions was the same. In addition, the substrate specificity, Km values and effect of inhibitory substances were identical. We conclude that sphingomyelinase is an acidic, microheterogeneous protein that likely exists as a holopolymer of a single major polypeptide chain. the heterogeneity of the intact protein on isoelectric focusing appears to reflect this microheterogeneity, which is influenced by a tendency to associate with itself and with detergents such as Triton X-100.

scholarly journals The primary structure of aspartate aminotransferase from pig heart muscle. Partial sequences determined by digestion with thermolysin and elastase

1973 ◽  
Vol 133 (4) ◽  
pp. 805-819 ◽  
Author(s):  
Francesco Bossa ◽  
Donatella Barra ◽  
Massimo Carloni ◽  
Paolo Fasella ◽  
Francesca Riva ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Primary Structure ◽  
Aspartate Aminotransferase ◽  
Heart Muscle ◽  
Science And Technology ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Lending Library

Peptides produced by thermolytic digestion of aminoethylated aspartate aminotransferase and of the oxidized enzyme were isolated and their amino acid sequences determined. Digestion by elastase of the carboxymethylated enzyme gave peptides representing approximately 40% of the primary structure. Fragments from these digests overlapped with previously reported sequences of peptides obtained by peptic and tryptic digestion (Doonan et al., 1972), giving ten composite peptides containing 395 amino acid residues. The amino acid composition of these composite peptides agrees well with that of the intact enzyme. Confirmatory results for some of the present data have been deposited as Supplementary Publication 50018 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973) 131, 5.

scholarly journals The cDNA and protein sequences of human lactate dehydrogenase B

1987 ◽  
Vol 248 (3) ◽  
pp. 933-936 ◽  
Author(s):  
I Sakai ◽  
F S Sharief ◽  
Y C Pan ◽  
S S Li
Keyword(s):  
Amino Acid ◽  
Lactate Dehydrogenase ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Amino Acid Sequences ◽  
British Library ◽  
Amino Acid Residues ◽  
Coding Region ◽  
Cdna Insert ◽  
Protein Coding

Human lactate dehydrogenase B (LDH-B) cDNA was isolated and sequenced. The LDH-B cDNA insert consists of the protein-coding sequence (999 bp), the 5′ (54 bp) and 3′ (203 bp) non-coding regions, and the poly(A) tail (50 bp). The predicted sequence of 333 amino acid residues was confirmed by amino acid composition and/or sequence analyses of a total of 185 (56%) residues from tryptic peptides of human LDH-B protein. The nucleotide and amino acid sequences of the human LDH-B coding region show 68% and 75% homologies respectively with those of the human LDH-A. The peptide map and amino acid composition data have been deposited as Supplementary Publication SUP 50139 (7 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies are available on prepayment [see Biochem. J. (1987) 241, 5].

scholarly journals Studies of haemoglobin types in barbary sheep (Ammotragus lervia)

1968 ◽  
Vol 107 (6) ◽  
pp. 745-751 ◽  
Author(s):  
G. van Vliet ◽  
T. H. J. Huisman ◽  
G. A. Dasher ◽  
W. H. Moretz ◽  
A. M. Dozy ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Domestic Sheep ◽  
Amino Acid Residues ◽  
Amino Acid Compositions ◽  
Ammotragus Lervia ◽  
Peptide T ◽  
Barbary Sheep ◽  
Β Chain

1. Two haemoglobin types, haemoglobins Amm-C and Amm-B, were observed in five Barbary sheep (Ammotragus lervia). One animal was homozygous for haemoglobin Amm-C, a second was homozygous for haemoglobin Amm-B, and three were heterozygous for both. 2. Amino acid analyses of the globin from haemoglobin Amm-B showed that this type was related to, but not identical with, haemoglobin B of the domestic sheep. 3. The β-chain of haemoglobin Amm-C was found to be composed of 141 amino acid residues. Its amino acid composition differed from that of the βC-chain of the anaemic domestic sheep in at least 14 residues. The Amm-βC-chain contained one isoleucyl residue. 4. The amino acid compositions of tryptic peptides T-1, T-2, T-13 and T-14 of the Amm-βC-chain were similar to those of the sheep βC-chain. Peptides T-3, T-4, T-6, T-7, T-8, T-11 and T-15 were the same as the corresponding peptides of the sheep βA- and βC-chains. Peptide T-5 and to a smaller extent peptide T-9 resembled the corresponding peptides of the sheep βA-chain, and peptide T-10 was identical with peptide γT-10 of sheep haemoglobin F. Peptide T-12 was not recovered. 5. The results of these investigations were interpreted as being indicative that the structural Amm-βC-gene is closely related to the βC-gene of sheep, from which through domestication the present domestic sheep originated.

scholarly journals Studies on Ovalbumin V. The Amino Acid Composition and Some Properties of Chicken, Duck, and Turkey Ovalbumins

1970 ◽  
Vol 23 (5) ◽  
pp. 1221 ◽  
Author(s):  
MB SmIth ◽  
Joan F Back
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Ammonium Sulphate ◽  
Acid Composition ◽  
Isoelectric Focusing ◽  
Ph Gradient ◽  
Ammonium Sulphate Fractionation

The ovalbumins from chicken, duck, and turkey eggs were prepared by ammonium sulphate fractionation and purified by isoelectric focusing in a pH gradient from 3 to 6. Amino acid analyses show a closer relationship between turkey and chicken ovalbumins than between duck and chicken ovalbumins.

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