Antifreeze proteins from the shorthorn sculpin, Myoxocephalus scorpius: isolation and characterization

1980 ◽  
Vol 58 (5) ◽  
pp. 377-383 ◽  
Author(s):  
Choy L. Hew ◽  
Garth L. Fletcher ◽  
V. S. Ananthanarayanan
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Secondary Structure ◽  
Antifreeze Proteins ◽  
Winter Flounder ◽  
Isolation And Characterization ◽  
Shorthorn Sculpin ◽  
Approximate Molecular Weight ◽  
Myoxocephalus Scorpius ◽  
Antifreeze Activity

The antifreeze proteins (AFP) of the shorthorn sculpin, Myoxocephalus scorpius, were isolated and compared with the AFP of the winter flounder. The shorthorn sculpin was found to contain one major and one minor antifreeze protein with an approximate molecular weight of 10 000 – 11 000 in the winter. The major AFP was isolated and characterized. It had many characteristics in common with the flounder AFP studied in our laboratories. These characteristics included its seasonal appearance, size, amino acid composition, the abundance of alanine in the composition, the extent of antifreeze activity, and the nature of the secondary structure. It is suggested that both the sculpin and flounder AFP are structurally homologous and belong to the same type of polypeptide antifreeze.

The relationship between molecular weight and antifreeze polypeptide activity in marine fish

1986 ◽  
Vol 64 (3) ◽  
pp. 578-582 ◽  
Author(s):  
Ming H. Kao ◽  
Garth L. Fletcher ◽  
Nam C. Wang ◽  
Choy L. Hew
Keyword(s):  
Molecular Weight ◽  
Thermal Hysteresis ◽  
Freezing Temperature ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Molecular Weights ◽  
Shorthorn Sculpin ◽  
Myoxocephalus Scorpius ◽  
Antifreeze Peptides ◽  
Antifreeze Activity

Previous studies have established that the capacity of the glycopeptide antifreezes to depress the freezing temperature of aqueous solutions is positively correlated with molecular weight. The present study was carried out to determine whether a similar correlation existed within the antifreeze peptides. Two approaches were used. Initially, the antifreeze activity (thermal hysteresis) curves of antifreeze peptides from winter flounder, Pseudopleuronectes americanus (molecular weight, 3300), shorthorn sculpin, Myoxocephalus scorpius (molecular weight, 4000), ocean pout, Macrozoarces americanus (molecular weight, 6000), and sea raven, Hemitripterus americanus (molecular weight, 9700), were compared. In the second approach, a more specific comparison was made of two different sized antifreeze peptide components (molecular weights, 2900 and 4000) from the shorthorn sculpin. In both approaches, antifreeze peptide activity was positively correlated with molecular weight and the curve illustrating this relationship suggests that any reduction in molecular weight below 3300 will result in a disproportionate decline in activity. The relatively small antifreeze peptides from the winter flounder and shorthorn sculpin had greater activity than did glycopeptide antifreezes of similar size. However, glycopeptide antifreezes with a molecular weight of 10 000 or more had activities that exceeded that of any known antifreeze peptide. Increases in molecular weight of antifreeze peptides above 4000 resulted in a decline in antifreeze activity per milligram protein. Therefore, in terms of ability to depress the freezing temperature, there appears to be no advantage in evolving large antifreeze peptide molecules.

scholarly journals α-Crystallin. The isolation and characterization of distinct macromolecular fractions

1971 ◽  
Vol 124 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Abraham Spector ◽  
Lu-Ku Li ◽  
Robert C. Augusteyn ◽  
Arthur Schneider ◽  
Thomas Freund
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Chemical Difference ◽  
Molecular Weights ◽  
Isolation And Characterization ◽  
Different Populations ◽  
Molecular Weight Fractions

α-Crystallin was isolated from calf lens periphery by chromatography on DEAE-cellulose and gel filtration. Three distinct populations of macromolecules have been isolated with molecular weights in the ranges approx. 6×105−9×105, 0.9×106−4×106and greater than 10×106. The concentration of macromolecules at the molecular-weight limits of a population are very low. The members of the different populations do not appear to be in equilibrium with each other. Further, in those molecular-weight fractions investigated, no equilibrium between members of the same population was observed. The population of lowest molecular weight comprises 65–75% of the total material. The amino acid and subunit composition of the different-sized fractions appear very similar, if not identical. The only chemical difference observed between the fractions is the presence of significant amounts of sugar in the higher-molecular-weight fractions. Subunit molecular weights of approx. 19.5×103and 22.5×103were observed for all α-crystallin fractions.

Isolation and characterization of some novel genes of the apolipoprotein A-I family in Japanese eel, Anguilla japonica

2011 ◽  
Vol 6 (4) ◽  
pp. 545-557 ◽  
Author(s):  
Malay Choudhury ◽  
Takahiro Oku ◽  
Shoji Yamada ◽  
Masaharu Komatsu ◽  
Keita Kudoh ◽  
...  
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Consensus Sequence ◽  
Structural Features ◽  
Lipid Binding ◽  
Japanese Eel ◽  
Amino Acid Sequences ◽  
Novel Genes ◽  
Isolation And Characterization

AbstractApolipoproteins such as apolipoprotein (apo) A-I, apoA-IV, and apoE are lipid binding proteins synthesized mainly in the liver and the intestine and play an important role in the transfer of exogenous or endogenous lipids through the circulatory system. To investigate the mechanism of lipid transport in fish, we have isolated some novel genes of the apoA-I family, apoIA-I (apoA-I isoform) 1–11, from Japanese eel by PCR amplification. Some of the isolated genes of apoIA-I corresponded to 28kDa-1 cDNAs which had already been deposited into the database and encoded an apolipoprotein with molecular weight of 28 kDa in the LDL, whereas others seemed to be novel genes. The structural organization of all apoIA-Is consisted of four exons separated by three introns. ApoIA-I10 had a total length of 3232 bp, whereas other genes except for apoIA-I9 ranged from 1280 to 1441 bp. The sequences of apoIA-Is at the exon-intron junctions were mostly consistent with the consensus sequence (GT/AG) at exon-intron boundaries, whereas the sequences of 3′ splice acceptor in intron 1 of apoIA-I1-7 were (AC) but not (AG). The deduced amino acid sequences of all apoIA-Is contained a putative signal peptide and a propeptide of 17 and 5 amino acid residues, respectively. The mature proteins of apoIA-I1-3, 7, and 8 consisted of 237 amino acids, whereas those of apoIA-I4-6 consisted of 239 amino acids. The mature apoIA-I10 sequence showed 65% identity to amino acid sequence of apoIA-I11 which was associated with an apolipoprotein with molecular weight of 23 kDa in the VLDL. All these mature apoIA-I sequences satisfied the common structural features depicted for the exchangeable apolipoproteins such as apoA-I, apoA-IV, and apoE but apoIA-I11 lacked internal repeats 7, 8, and 9 when compared with other members of apoA-I family. Phylogenetic analysis showed that these novel apoIA-Is isolated from Japanese eel were much closer to apoA-I than apoA-IV and apoE, suggesting new members of the apoA-I family.

Antifreeze Proteins in the Arctic Shorthorn Sculpin (Myoxocephalus scorpius)

ARCTIC ◽  
1982 ◽  
Vol 35 (2) ◽  
Author(s):  
Garth L. Fletcher ◽  
Richard F. Addison ◽  
Don Slaughter ◽  
Choy L. Hew
Keyword(s):  
Antifreeze Proteins ◽  
The Arctic ◽  
Shorthorn Sculpin ◽  
Myoxocephalus Scorpius

How does the brain control the pituitary's release of antifreeze synthesis inhibitor?

1984 ◽  
Vol 62 (5) ◽  
pp. 839-844 ◽  
Author(s):  
G. L. Fletcher ◽  
M. J. King ◽  
C. L. Hew
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Antifreeze Proteins ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Synthesis Inhibitor ◽  
Pituitary Glands ◽  
The Central Nervous System ◽  
The Brain ◽  
Antifreeze Activity

Previous studies of winter flounder (Pseudopleuronectes americanus) demonstrated that the pituitary inhibits the synthesis of antifreeze proteins during the summer and that the inhibition is removed with the approach of winter. Assuming that the pituitary is under the control of the central nervous system, the question posed was, Does the central nervous system stimulate the release of the pituitary antifreeze inhibitory factor during the summer or inhibit its release during the winter? Two experiments were carried out. In the first, flounder were hypophysectomized and a number of them were given pituitary autotransplants prior to the spring loss of plasma antifreeze. During July, flounder containing functional autotransplants had lost the capacity to synthesize antifreeze proteins and their plasma antifreeze activity had disappeared. In the second experiment, hypophysectomy and pituitary transplantation was carried out in the fall prior to the winter onset of antifreeze biosynthesis. Flounder containing functional auto- or homo-transplants showed no evidence of plasma antifreeze activity, whereas intact controls and hypophysectomized flounder had levels typical of winter fish. These results indicate that the central nervous system normally inhibits the pituitary glands release of antifreeze inhibitor during the winter.

Isolation and characterization of full-length functional cDNA clones for human carcinoembryonic antigen

1987 ◽  
Vol 7 (9) ◽  
pp. 3221-3230
Author(s):  
N Beauchemin ◽  
S Benchimol ◽  
D Cournoyer ◽  
A Fuks ◽  
C P Stanners
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Carcinoembryonic Antigen ◽  
Full Length ◽  
Cdna Clones ◽  
Base Pairs ◽  
Amino Terminal ◽  
Isolation And Characterization

Carcinoembryonic antigen (CEA) expression is perhaps the most prevalent of phenotypic changes observed in human cancer cells. The molecular genetic basis of this phenomenon, however, is completely unknown. Twenty-seven CEA cDNA clones were isolated from a human colon adenocarcinoma cell line. Most of these clones are full length and consist of a number (usually three) of surprisingly similar long (534 base pairs) repeats between a 5' end of 520 base pairs and a 3' end with three different termination points. The predicted translation product of these clones consists of a processed signal sequence of 34 amino acids, an amino-terminal sequence of 107 amino acids, which includes the known terminal amino acid sequence of CEA, three repeated domains of 178 amino acids each, and a membrane-anchoring domain of 27 amino acids, giving a total of 702 amino acids and a molecular weight of 72,813 for the mature protein. The repeated domains have conserved features, including the first 67 amino acids at their N termini and the presence of four cysteine residues. Comparisons with the amino acid sequences of other proteins reveals homology of the repeats with various members of the immunoglobulin supergene family, particularly the human T-cell receptor gamma chain. CEA cDNA clones in the SP-65 vector were shown to produce transcripts in vitro which could be translated in vitro to yield a protein of molecular weight 73,000 which in turn could be precipitated with CEA-specific antibodies. CEA cDNA clones were also inserted into an animal cell expression vector and introduced by transfection into mammalian cell lines. These transfectants produced a CEA-immunoprecipitable glycoprotein which could be visualized by immunofluorescence on the cell surface.

Isolation and characterization of β-lipolytic hormone from porcine pituitary gland

1970 ◽  
Vol 48 (9) ◽  
pp. 1017-1021 ◽  
Author(s):  
C. Gilardeau ◽  
M. Chrétien
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Pituitary Gland ◽  
Amino Acid Composition ◽  
Biological Activities ◽  
Terminal Amino Acid ◽  
Isolation And Characterization ◽  
Pituitary Glands ◽  
Terminal Amino

A lipolytic substance was isolated from porcine pituitary glands. It's amino acid composition, molecular weight, N-terminal amino acid, isoelectric point, and biological activities are reported. These results are compared to the corresponding values of sheep β-lipolytic hormone.

Isolation and characterization of the principal caseins in rat milk

1980 ◽  
Vol 47 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Jean-Pierre Pelissier ◽  
Ahmed Yahia ◽  
Jean-Marc Chobert ◽  
Bruno Ribadeau Dumas
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Molecular Weight Determination ◽  
Terminal Sequence ◽  
Sequence Determination ◽  
Sialic Acid Content ◽  
Isolation And Characterization ◽  
The Individual ◽  
Similar Peptide

SummaryThe 4 major caseins, A1, A2, B1, B2, from rat milk have been isolated and analysed. From molecular weight determination, amino acid and phosphorus analyses and N-terminal sequence determination, A1 and A2 are concluded to possess similar peptide chains as do B1 and B2, with the individual fractions within each of these 2 groups differing only in their sialic acid content.Mol. wts of approximately 22000 and 38000 were found for A1–A2 and B1–B2 respectively. The amino acid sequence of the first 13 residues of A1–A2 has been partly established. Components A1 and A2 appeared to be homologous with bovine β-casein, whereas B1 and B2 were different from any known casein, especially in their molecular weight.

scholarly journals Isolation and characterization of full-length functional cDNA clones for human carcinoembryonic antigen.

1987 ◽  
Vol 7 (9) ◽  
pp. 3221-3230 ◽  
Author(s):  
N Beauchemin ◽  
S Benchimol ◽  
D Cournoyer ◽  
A Fuks ◽  
C P Stanners
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Carcinoembryonic Antigen ◽  
Full Length ◽  
Cdna Clones ◽  
Base Pairs ◽  
Amino Terminal ◽  
Isolation And Characterization

Carcinoembryonic antigen (CEA) expression is perhaps the most prevalent of phenotypic changes observed in human cancer cells. The molecular genetic basis of this phenomenon, however, is completely unknown. Twenty-seven CEA cDNA clones were isolated from a human colon adenocarcinoma cell line. Most of these clones are full length and consist of a number (usually three) of surprisingly similar long (534 base pairs) repeats between a 5' end of 520 base pairs and a 3' end with three different termination points. The predicted translation product of these clones consists of a processed signal sequence of 34 amino acids, an amino-terminal sequence of 107 amino acids, which includes the known terminal amino acid sequence of CEA, three repeated domains of 178 amino acids each, and a membrane-anchoring domain of 27 amino acids, giving a total of 702 amino acids and a molecular weight of 72,813 for the mature protein. The repeated domains have conserved features, including the first 67 amino acids at their N termini and the presence of four cysteine residues. Comparisons with the amino acid sequences of other proteins reveals homology of the repeats with various members of the immunoglobulin supergene family, particularly the human T-cell receptor gamma chain. CEA cDNA clones in the SP-65 vector were shown to produce transcripts in vitro which could be translated in vitro to yield a protein of molecular weight 73,000 which in turn could be precipitated with CEA-specific antibodies. CEA cDNA clones were also inserted into an animal cell expression vector and introduced by transfection into mammalian cell lines. These transfectants produced a CEA-immunoprecipitable glycoprotein which could be visualized by immunofluorescence on the cell surface.

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