scholarly journals Purification and amino acid sequence of melanocyte-stimulating hormone from the dogfish Squalus acanthias

1970 ◽  
Vol 118 (5) ◽  
pp. 713-718 ◽  
Author(s):  
P. J. Lowry ◽  
A. Chadwick

A melanocyte-stimulating hormone (MSH) was isolated by gel filtration and ion-exchange chromatography from extracts of the pituitary glands of dogfish. Sequence studies were carried out on the hormone and its enzymically and chemically cleaved fragments. The sequence of the hormone, Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Met, shows that ten of its 11 residues are the same as ten of the 13 residues of mammalian α-MSH. About half of its molecules have the carboxyl group at the C-terminus free and about half are amidated; about a fifth have an extra tyrosine residue on the N-terminus, thereby making 11 residues the same as in mammalian α-MSH. Unlike the mammalian hormone, however, none of it was found to be N-acetylated.

1974 ◽  
Vol 141 (2) ◽  
pp. 439-444 ◽  
Author(s):  
Hugh P. J. Bennett ◽  
Philip J. Lowry ◽  
Colin McMartin ◽  
Alexander P. Scott

A melanocyte-stimulating hormone (MSH) has been isolated from extracts of the neurointermediate lobe of the pituitary of the dogfish Squalus acanthias by gel-filtration and ion-exchange chromatography. It had approximately 1% of the potency of mammalian α-MSH on bioassays in vitro on frog skin and dogfish skin. Sequence analysis revealed it to be a hexadecapeptide with the following primary structure: Asp-Gly-Asp-Asp-Tyr-Lys-Phe-Gly-His-Phe-Arg-Trp-Ser-Val-Pro-Leu. It appears to be related to the β-MSH species of mammalian species but has only the sequence -His-Phe-Arg-Trp- in common with the heptapeptide core -Met-Glu-His-Phe-Arg-Trp-Gly- which is characteristic not only of the MSH peptides but also of the adrenocorticotrophins and lipotrophins studied so far. An α-MSH was also isolated, 50% of which was amidated at the C-terminus group. Sequence data from this study taken in conjunction with those from a previous study (Lowry & Chadwick, 1970b) revealed it to be a tridecapeptide which is identical with the N-terminal sequence of dogfish adrenocorticotrophin.


1985 ◽  
Vol 50 (6) ◽  
pp. 1329-1334
Author(s):  
Jaroslav Vičar ◽  
Linda Servítová ◽  
Martin Flegel ◽  
Karel Hauzer ◽  
Tomislav Barth

Analogues of [5-Leu]enkephalin, prolonged by methionine on the N-terminus or, by lysine or methionine on the C-terminus were prepared by fragment condensation, purified by ion exchange chromatography or high-pressure liquid chromatography. The substances were characterised by their opioid activity in a test on guinea-pig ileum in comparison with the activity of [5-Leu]enkephalin.


1974 ◽  
Vol 141 (2) ◽  
pp. 427-437 ◽  
Author(s):  
Philip J. Lowry ◽  
Hugh P. J. Bennett ◽  
Colin McMartin ◽  
Alexander P. Scott

An adrenocorticotrophic hormone (ACTH) was isolated from extracts of the pars distalis of the pituitary of the dogfish Squalus acanthias by gel filtration and ion-exchange chromatography. It had 15% of the potency of human ACTH in promoting cortico-steroidogenesis in isolated rat adrenal cells. Sequence analysis revealed it to be a nonatria-contapeptide with the following primary structure: Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Met-Gly-Arg-Lys-Arg-Arg-Pro-Ile-Lys-Val-Tyr-Pro-Asn-Ser-Phe-Glu-Asp-Glu-Ser-Val-Glu-Asn-Met-Gly-Pro-Glu-Leu. The N-terminal tridecapeptide sequence was identical with the proposed structure of dogfish α-melanocyte-stimulating hormone (α-MSH). On comparison with human ACTH eleven amino acid differences were seen, nine of which are in the 20–39 region of the molecule which is not essential for the steroidogenic activity of ACTH. A peptide identical with the 18–39 portion of this new ACTH was similarly isolated from the neurointermediate lobe of the pituitary where considerable amounts of dogfish α-MSH were found. This supported our view that ACTH as well as having a distinct biological role of its own is also the precursor of α-MSH.


1972 ◽  
Vol 53 (1) ◽  
pp. 95-100 ◽  
Author(s):  
ANNE STOCKELL HARTREE ◽  
MARJORIE THOMAS ◽  
BRIDGET E. FURNIVAL ◽  
T. W. BURNS ◽  
P. LANGLEY

SUMMARY A partially purified fraction of human thyroid-stimulating hormone (DEAE-II) was further purified by ion-exchange chromatography on IRC-50, gel-filtration on Sephadex G-100 and finally chromatography on DEAE-cellulose. Two fractions were obtained which were high in thyroid-stimulating activity (8·3 and 7·3 units human Research Standard A/mg) and were comparable in potency to other preparations of the human hormone reported in the literature. They were also electrophoretically heterogeneous as were the preparations of other workers. Lipolytic activity toward cells obtained from human or rat adipose tissue was demonstrated for all fractions containing thyroid-stimulating activity, the two activities being roughly parallel. It is concluded that both thyroid-stimulating and lipolytic activities are probably present in the same protein molecule, but it is unlikely that the latter activity is of physiological significance.


1974 ◽  
Vol 52 (5) ◽  
pp. 349-358 ◽  
Author(s):  
X. Bertagna ◽  
M. Lis ◽  
C. Gilardeau ◽  
M. Chrétien

Sheep beta-lipotropic hormone (β-LPH) is a pituitary hormone made of 90 amino acids and having a portion of its sequence (41–58) identical with the structure of beta-melanocyte-stimulating hormone (β-MSH). We hypothetized that β-LPH could be the biological precursor of β-MSH. We studied the biosynthesis of these two molecules by monitoring the incorporation of radioactive amino acids in beef pituitary slices. We separated β-LPH from the other radioactive proteins with the usual method of purification described previously and we characterized the proteins by ion-exchange chromatography, gel filtration, and polyacrylamide gel electrophoresis. Our results show that the pituitary slices synthesized a radioactive β-LPH which has all the characteristics of non-radioactive β-LPH. However, in the conditions used, we could not demonstrate any biosynthesis of β-MSH after 4 h incubation. These results suggest that the conversion of β-LPH into β-MSH, if it exists, is a slow process and should be studied in more prolonged incubations.


2000 ◽  
Vol 66 (1) ◽  
pp. 23-28 ◽  
Author(s):  
M. Beukes ◽  
G. Bierbaum ◽  
H.-G. Sahl ◽  
J. W. Hastings

ABSTRACT Streptococcus milleri NMSCC 061 was screened for antimicrobial substances and shown to produce a bacteriolytic cell wall hydrolase, termed millericin B. The enzyme was purified to homogeneity by a four-step purification procedure that consisted of ammonium sulfate precipitation followed by gel filtration, ultrafiltration, and ion-exchange chromatography. The yield following ion-exchange chromatography was 6.4%, with a greater-than-2,000-fold increase in specific activity. The molecular weight of the enzyme was 28,924 as determined by electrospray mass spectrometry. The amino acid sequences of both the N terminus of the enzyme (NH2 SENDFSLAMVSN) and an internal fragment which was generated by cyanogen bromide cleavage (NH2 SIQTNAPWGL) were determined by automated Edman degradation. Millericin B displayed a broad spectrum of activity against gram-positive bacteria but was not active againstBacillus subtilis W23 or Escherichia coli ATCC 486 or against the producer strain itself. N-Dinitrophenyl derivatization and hydrazine hydrolysis of free amino and free carboxyl groups liberated from peptidoglycan digested with millericin B followed by thin-layer chromatography showed millericin B to be an endopeptidase with multiple activities. It cleaves the stem peptide at the N terminus of glutamic acid as well as the N terminus of the last residue in the interpeptide cross-link of susceptible strains.


1968 ◽  
Vol 42 (1) ◽  
pp. 143-NP ◽  
Author(s):  
B. T. PICKERING

SUMMARY A protein capable of binding neurohypophysial hormones has been isolated from cod pituitary glands using gel filtration and ion-exchange chromatography. The cod protein which was acidic and rich in cystine had an amino acid composition closely related to those of the mammalian neurophysins. It had a maximum binding capacity of 2·2 μmole/14mg. for oxytocin, 2·1 μmole/14 mg. for [8-arginine]-oxytocin and 1·1 μmole/14 mg. for [8-arginine]-vasopressin. Thus the cod protein had a greater capacity for the endogenous pressor-antidiuretic peptide than for the analogous mammalian hormone.


1973 ◽  
Vol 30 (02) ◽  
pp. 414-424 ◽  
Author(s):  
Ulla Hedner

SummaryA procedure is described for partial purification of an inhibitor of the activation of plasminogen by urokinase and streptokinase. The method involves specific adsorption of contammants, ion-exchange chromatography on DEAE-Sephadex, gel filtration on Sephadex G-200 and preparative electrophoresis. The inhibitor fraction contained no antiplasmin, no plasminogen, no α1-antitrypsin, no antithrombin-III and was shown not to be α2 M or inter-α-inhibitor. It contained traces of prothrombin and cerulo-plasmin. An antiserum against the inhibitor fraction capable of neutralising the inhibitor in serum was raised in rabbits.


1984 ◽  
Vol 51 (01) ◽  
pp. 016-021 ◽  
Author(s):  
S Birken ◽  
G Agosto ◽  
B Lahiri ◽  
R Canfield

SummaryIn order to investigate the early release of NH2-terminal plasmic fragments from the Bβ chain of fibrinogen, substantial quantities of Bβ 1-42 and Bβ 1-21 are required as immunogens, as radioimmunoassay standards and for infusion into human volunteers to determine the half-lives of these peptides. Towards this end methods that employ selective proteolytic cleavage of these fragments from fibrinogen have been developed. Both the N-DSK fragment, produced by CNBr cleavage of fibrinogen, and Bβ 1-118 were employed as substrates for plasmin with the finding of higher yields from N-DSK. Bβ 1-42 and Bβ 1-21 were purified by gel filtration and ion-exchange chromatography on SP-Sephadex using volatile buffers. When the purified preparation of Bβ 1-42 was chromatographed on reverse-phase high performance liquid chromatography, two peaks of identical amino acid composition were separated, presumably due either to pyroglutamate or to amide differences.


1984 ◽  
Vol 49 (8) ◽  
pp. 1846-1853 ◽  
Author(s):  
Karel Hauzer ◽  
Tomislav Barth ◽  
Linda Servítová ◽  
Karel Jošt

A post-proline endopeptidase (EC 3.4.21.26) was isolated from pig kidneys using a modified method described earlier. The enzyme was further purified by ion exchange chromatography on DEAE-Sephacel. The final product contained about 95% of post-proline endopeptidase. The enzyme molecule consisted of one peptide chain with a relative molecular mass of 65 600 to 70 000, containing a large proportion of acidic and alifatic amino acids (glutamic acid, aspartic acid and leucine) and the N-terminus was formed by aspartic acid or asparagine. In order to prevent losses of enzyme activity, thiol compounds has to be added.


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