Human pituitary thyrotropin. The primary structure of the α and β subunits

1977 ◽  
Vol 55 (7) ◽  
pp. 755-760 ◽  
Author(s):  
M. R. Sairam ◽  
Choh Hao Li
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Primary Structure ◽  
Carbohydrate Moiety ◽  
Amino Acid Residues ◽  
Β Subunit ◽  
Human Pituitary ◽  
Α Subunit ◽  
Α And Β Subunits

The amino acid sequence of the α and β subunits of human pituitary thyrotropin has been proposed based on the data derived from the tryptic and chymotryptic peptides. The α subunit consists of 89 amino acid residues with two carbohydrate moieties, presumably linked to asparagines in position 49 and 75, and its amino acid sequence is identical to that of lutropin α. The β subunit has 112 residues with a single carbohydrate moiety attached to asparagine at position 23. Comparison of the primary structure of human thyrotropin β with that of the bovine hormone reveals that only 11 residue positions have been found to be different.

scholarly journals Amino acid sequence of the α subunit and computer modelling of the α and β subunits of echicetin from the venom of Echis carinatus (saw-scaled viper)

1997 ◽  
Vol 323 (2) ◽  
pp. 533-537 ◽  
Author(s):  
János POLGÁR ◽  
Edith M. MAGNENAT ◽  
Manuel C. PEITSCH ◽  
Timothy N. C. WELLS ◽  
Mansoor S. A. SAQI ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Computer Modelling ◽  
Platelet Glycoprotein ◽  
Β Subunit ◽  
Α Subunit ◽  
Echis Carinatus ◽  
Α And Β Subunits ◽  
Lectin Protein ◽  
Von Willebrand

Echicetin, a heterodimeric protein from the venom of Echis carinatus, binds to platelet glycoprotein Ib (GPIb) and so inhibits platelet aggregation or agglutination induced by various platelet agonists acting via GPIb. The amino acid sequence of the β subunit of echicetin has been reported and found to belong to the recently identified snake venom subclass of the C-type lectin protein family. Echicetin α and β subunits were purified. N-terminal sequence analysis provided direct evidence that the protein purified was echicetin. The paper presents the complete amino acid sequence of the α subunit and computer models of the α and β subunits. The sequence of α echicetin is highly similar to the α and β chains of various heterodimeric and homodimeric C-type lectins. Neither of the fully reduced and alkylated α or β subunits of echicetin inhibited the platelet agglutination induced by von Willebrand factor–ristocetin or α-thrombin. Earlier reports about the inhibitory activity of reduced and alkylated echicetin β subunit might have been due to partial reduction of the protein.

Partial cDNA sequence for the donkey chorionic gonadotrophin-β subunit suggests evolution from an ancestral LH-β gene

1990 ◽  
Vol 4 (2) ◽  
pp. 143-150 ◽  
Author(s):  
S. E. A. Leigh ◽  
F. Stewart
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Dna Sequences ◽  
Biological Activities ◽  
Chorionic Gonadotrophin ◽  
Amino Acid Residues ◽  
Β Subunit ◽  
Coding Region ◽  
Amino Acid Homology ◽  
Nucleotide Insertions

ABSTRACT A 246 bp cDNA clone representing the C-terminal region of the donkey (Equus asinus) chorionic gonadotrophin (CG)-β subunit was isolated from a placental library. The transcript contained the 3′ untranslated region and 42% of the CG-β subunit coding region (amino acid residues 85–146 of the mature peptide). Comparison of the deduced donkey amino acid sequence with the published horse CG-β subunit protein sequence (where they overlapped) revealed an overall homology of 61%. However, most of the differences were in the C-terminal extension, which is thought not to be important for gonadotrophic activity, and appeared to be due to two nucleotide insertions in the donkey sequence (compared with a deduced horse nucleotide sequence) leading to a reading-frame shift. Amino acid homology in the disulphide 'core' region was 81%. Some of the differences in this region were in the 'determinant loop' (residues 93–100) and these are interpreted in relation to the observed biological activities of horse and donkey CG. The deduced amino acid sequence of the donkey cDNA indicated that it was larger than the majority of gonadotrophin-β subunits due to a C-terminal extension. Primate and horse CG (and horse LH) β subunits have analogous C-terminal extensions. The extension in the donkey subunit is 25 amino acid residues in length, compared with 28 in the horse and 24 in man. Comparisons with other available subunit DNA sequences indicated that, like the human CG-β gene, the donkey gene probably evolved from an ancestral LH-like β gene, following nucleotide deletions that allowed readthrough into previously untranslated DNA. Furthermore, both the human and donkey CG-β genes make use of the original LH polyadenylation sequence AAUAAA for translational termination and polyadenylation. We conclude that the C-terminal extension arose independently in equids and primates but through similar mechanisms.

scholarly journals On the Primary Structure of Human Fibrinogen

1977 ◽  
Author(s):  
A. Henschen ◽  
F. Lottspeich ◽  
E. Töpfer-Petersen ◽  
R. Warbinek
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Primary Structure ◽  
Cyanogen Bromide ◽  
Attachment Site ◽  
Complete Sequence ◽  
Cleavage Sites ◽  
Amino Acid Residues ◽  
Human Fibrinogen ◽  
Β Chain

The aim of the present investigation is to elucidate the primary structure of human fibrinogen. Through the work of several laboratories including our own large parts of the structure are now known. Here will be reported the complete amino acid sequence of the γ-chain (409 residues). Furthermore, the carbohydrate linkage site in the β-chain and plasmin cleavage sites in the β- and γ-chains have been identified.The peptide chains were isolated by CM-cellulose chromatography following mercaptolysis and alkylation. The γ-chain was cleaved in a way to produce large fragments suitable for automatic sequencing, e. g. with cyanogen bromide or trypsin after citraconylation. The sequences of the isolated fragments allowed reconstruction of the complete sequence of the γ-chain.The carbohydrate linkage site in the β-chain could be isolated by affinity chromatography on concanavalin A-agarose following cleavage of the chain by trypsin or cyanogen bromide. The sequence of 21 amino acid residues around the carbohydrate attachment site was determined.The plasmin cleavage site giving rise to N-terminal glycine in the γ-chain D-fragment was identified. The amino acid sequence linking plasmic fragments E and D in the β-chain was determined.

The amino acid sequence of wheat β-purothionin

1976 ◽  
Vol 54 (10) ◽  
pp. 835-842 ◽  
Author(s):  
A. S. Mak ◽  
B. L. Jones
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Primary Structure ◽  
Basic Protein ◽  
Viscum Album ◽  
Low Molecular Weight ◽  
Amino Acid Residues ◽  
Basic Proteins ◽  
Considerable Homology

The complete amino acid sequence of β-purothionin, a low molecular weight, very basic, protein isolated from wheat endosperm material, has been determined. β-purothionin is toxic to some bacteria, to yeasts, and to animals when injected. The protein contains 45 amino acid residues and has a molecular weight of 4913. The 8 cysteine and 10 basic residues are distributed throughout the molecule. The primary structure of the protein shows considerable homology to those of the viscotoxins, which are toxic, small, basic proteins found in the leaves and stems of European mistletoe (Viscum album L.).

Lysine residues 2 and 104 of the human chorionic gonadotrophin β subunit influence receptor binding

1993 ◽  
Vol 10 (3) ◽  
pp. 337-343 ◽  
Author(s):  
H Xia ◽  
J Huang ◽  
T-M Chen ◽  
D Puett
Keyword(s):  
Amino Acid ◽  
Receptor Binding ◽  
Basic Amino Acid ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Amino Acid Residues ◽  
Β Subunit ◽  
Wild Type ◽  
Α Subunit ◽  
Lysine Residues

ABSTRACT Human chorionic gonadotrophin (hCG), like other members of the glycoprotein hormone family, contains a common α subunit and a hormone-specific β subunit. The latter is a 145 amino acid residue polypeptide with six sites of glycosylation. Positions 2 and 104 are occupied by basic amino acid residues in the 12 known amino acid sequences of mammalian β subunits from CG and LH, a related gonadotrophin that acts through the same receptor. Lysine residues are found in both these positions in hCG-β. Using site-directed mutagenesis, each of these two lysines in hCG-β was replaced with glutamic acid. The mutant and wild-type cDNAs were subcloned into a eukaryotic expression vector, which was then transiently transfected into Chinese hamster ovary cells containing a stably integrated gene for the bovine α subunit. Holoprotein formation occurred with each of the two heterologous gonadotrophin mutants, i.e. the bovine α subunit bound to hCG-β (Glu2) and to hCG-β (Glu104), as well as with the control, i.e. the bovine α subunit bound to the hCG-β wild-type subunit. In two in-vitro assays, one a competitive binding assay with 125I-labelled hCG as bound ligand and the other based on stimulation of progesterone production in a transformed murine Leydig cell line, MA-10, both the heterodimers containing a mutant β subunit exhibited bioactivity, but their potencies were lower than that of the bovine α subunit bound to the hCG-β wild-type subunit. These results suggest that the basic amino acid residues at positions 2 and 104 in hCG-β participate, either directly or indirectly, in receptor binding.

Phosphorylation, glycosylation and amino acid sequence of component PP3 from the proteose peptone fraction of bovine milk

1993 ◽  
Vol 60 (4) ◽  
pp. 535-542 ◽  
Author(s):  
Esben S. Sørensen ◽  
Torben E. Petersen
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Molecular Mass ◽  
Primary Structure ◽  
Bovine Milk ◽  
Amino Sugar ◽  
Amino Sugars ◽  
Amino Acid Residues ◽  
Proteose Peptone ◽  
Amino Acid Analyser

SummaryComponent PP3 is a phosphorylated glycoprotein with an apparent molecular mass of 28 kDa isolated from the proteose peptone fraction of bovine milk. The function of the protein is not known. The primary structure has been determined and shown to contain 135 amino acid residues (EMBL accession no. P80195). It was phosphorylated at Ser29, Ser34, Ser38, Ser40 and Ser46. Two O-linked carbohydrate groups were found at Thr16 and Thr86, while one N-linked carbohydrate group was present at Asn77. Thr16 was only ∼ 50% glycosylated. The amino sugar detected by the amino acid analyser at Thr86 was mainly galactosamine but a small amount of glucosamine was also present. The amino sugars found in the carbohydrate group linked to Asn77 were both glucosamine and galactosamine. A fragment of PP3 has been isolated from milk and shown to correspond to residues 54–135. This fragment was probably generated by plasmin hydrolysing the Arg53–Ser54 bond.

scholarly journals N-Terminal amino acid sequence of the α-subunit of human pituitary luteinizing hormone

1972 ◽  
Vol 126 (2) ◽  
pp. 441-442 ◽  
Author(s):  
T Inagami ◽  
K Murakami ◽  
D Puett ◽  
A S Hartree ◽  
A Nureddin
Keyword(s):  
Amino Acid ◽  
Luteinizing Hormone ◽  
Amino Acid Sequence ◽  
Terminal Amino Acid ◽  
Human Pituitary ◽  
Α Subunit ◽  
Terminal Amino ◽  
Terminal Amino Acid Sequence

Amino acid sequence of cyanogen bromide fragment CB5 of human hemopexin

1989 ◽  
Vol 54 (3) ◽  
pp. 803-810 ◽  
Author(s):  
Ivan Kluh ◽  
Ladislav Morávek ◽  
Manfred Pavlík
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Acid Hydrolysis ◽  
Cyanogen Bromide ◽  
Polypeptide Chain ◽  
Amino Acid Residues ◽  
Mild Acid Hydrolysis ◽  
Methionine Residue ◽  
Cyanogen Bromide Fragment ◽  
Mild Acid

Cyanogen bromide fragment CB5 represents the region of the polypeptide chain of hemopexin between the fourth and fifth methionine residue (residues 232-352). It contains 120 amino acid residues in the following sequence: Arg-Cys-Ser-Pro-His-Leu-Val-Leu-Ser-Ala-Leu-Thr-Ser-Asp-Asn-His-Gly-Ala-Thr-Tyr-Ala-Phe-Ser-Gly-Thr-His-Tyr-Trp-Arg-Leu-Asp-Thr-Ser-Arg-Asp-Gly-Trp-His-Ser-Trp-Pro-Ile-Ala-His-Gln-Trp-Pro-Gln-Gly-Pro-Ser-Ala-Val-Asp-Ala-Ala-Phe-Ser-Trp-Glu-Glu-Lys-Leu-Tyr-Leu-Val-Gln-Gly-Thr-Gln-Val-Tyr-Val-Phe-Leu-Thr-Lys-Gly-Gly-Tyr-Thr-Leu-Val-Ser-Gly-Tyr-Pro-Lys-Arg-Leu-Glu-Lys-Glu-Val-Gly-Thr-Pro-His-Gly-Ile-Ile-Leu-Asp-Ser-Val-Asp-Ala-Ala-Phe-Ile-Cys-Pro-Gly-Ser-Ser-Arg-Leu-His-Ile-Met. The sequence was derived from the data on peptides prepared by cleavage of fragment CB5 by mild acid hydrolysis, by trypsin and chymotrypsin.

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