Purification and characterization of insulin, glucagon, and two glucagon-like peptides with insulin-releasing activity from the pancreas of the toad, Bufo marinus

JM Conlon, Yasser Abdel-Wahab, FPM O'Harte, PF Nielsen, J Whittaker

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Insulin and four peptides derived from the posttranslational processing of proglucagon have been isolated in pure form from the pancreas of the cane toad, Bufo marinus. Although Bufo insulin contains 9 amino acid substitutions, compared with human insulin, all those residues that are considered to be involved in receptor-binding and in dimer and hexamer formation have been conserved. Bufo insulin was, however, more potent (4-fold) than human insulin in inhibiting the binding of [I-125-Tyr-A14] insulin to the soluble full-length recombinant human insulin receptor, which is probably a consequence of the substitution (Thr --> Kis) at position A-8. Bufo glucagon was isolated in two molecular forms: glucagon-29 shows only one amino acid substitution (Thr29 --> Ser), compared with human glucagon; and glucagon-36 comprises glucagon-29, extended from its C-terminus by Lys-Arg-Ser-Gly-Gly-Met-Ser. The human proglucagon gene contains one copy of glucagon-like peptide (GLP)-1, a potent insulin secretogogue, and one copy of GLP-2 that is devoid of insulin-releasing activity. In contrast, two proglucagon-derived peptides with 32- and 37-amino acid residues (GLP-32 and GLP-37), displaying greater structural similarity to human GLP-1 than to GLP-2, were isolated from Bufo pancreas. Both peptides produced concentration-dependent increases in insulin release from glucose-responsive rat insulinoma-derived BRIN-BD11 cells. The threshold concentrations producing a significant (P < 0.001) effect were 10(-8) M (GLP-32) and 10(-9) M (GLP-37), and the maximum increase in the rate of insulin release produced by 10(-6) M concentrations of both peptides was approximately 5-fold.
LanguageEnglish
Pages3442-3448
JournalEndocrinology
Volume139
Issue number8
Publication statusPublished - Aug 1998

Fingerprint

Bufo marinus
Glucagon-Like Peptides
Glucagon
Anura
Pancreas
Insulin
Bufonidae
Proglucagon
Glucagon-Like Peptide 2
Glucagon-Like Peptide 1
Amino Acid Substitution
Peptides
Canes
Insulinoma

Cite this

@article{f030abbe74f64023bdef77709edd0d95,
title = "Purification and characterization of insulin, glucagon, and two glucagon-like peptides with insulin-releasing activity from the pancreas of the toad, Bufo marinus",
abstract = "Insulin and four peptides derived from the posttranslational processing of proglucagon have been isolated in pure form from the pancreas of the cane toad, Bufo marinus. Although Bufo insulin contains 9 amino acid substitutions, compared with human insulin, all those residues that are considered to be involved in receptor-binding and in dimer and hexamer formation have been conserved. Bufo insulin was, however, more potent (4-fold) than human insulin in inhibiting the binding of [I-125-Tyr-A14] insulin to the soluble full-length recombinant human insulin receptor, which is probably a consequence of the substitution (Thr --> Kis) at position A-8. Bufo glucagon was isolated in two molecular forms: glucagon-29 shows only one amino acid substitution (Thr29 --> Ser), compared with human glucagon; and glucagon-36 comprises glucagon-29, extended from its C-terminus by Lys-Arg-Ser-Gly-Gly-Met-Ser. The human proglucagon gene contains one copy of glucagon-like peptide (GLP)-1, a potent insulin secretogogue, and one copy of GLP-2 that is devoid of insulin-releasing activity. In contrast, two proglucagon-derived peptides with 32- and 37-amino acid residues (GLP-32 and GLP-37), displaying greater structural similarity to human GLP-1 than to GLP-2, were isolated from Bufo pancreas. Both peptides produced concentration-dependent increases in insulin release from glucose-responsive rat insulinoma-derived BRIN-BD11 cells. The threshold concentrations producing a significant (P < 0.001) effect were 10(-8) M (GLP-32) and 10(-9) M (GLP-37), and the maximum increase in the rate of insulin release produced by 10(-6) M concentrations of both peptides was approximately 5-fold.",
author = "JM Conlon and Yasser Abdel-Wahab and FPM O'Harte and PF Nielsen and J Whittaker",
year = "1998",
month = "8",
language = "English",
volume = "139",
pages = "3442--3448",
journal = "Endocrinology",
issn = "0013-7227",
publisher = "Endocrine Society",
number = "8",

}

TY - JOUR

T1 - Purification and characterization of insulin, glucagon, and two glucagon-like peptides with insulin-releasing activity from the pancreas of the toad, Bufo marinus

AU - Conlon, JM

AU - Abdel-Wahab, Yasser

AU - O'Harte, FPM

AU - Nielsen, PF

AU - Whittaker, J

PY - 1998/8

Y1 - 1998/8

N2 - Insulin and four peptides derived from the posttranslational processing of proglucagon have been isolated in pure form from the pancreas of the cane toad, Bufo marinus. Although Bufo insulin contains 9 amino acid substitutions, compared with human insulin, all those residues that are considered to be involved in receptor-binding and in dimer and hexamer formation have been conserved. Bufo insulin was, however, more potent (4-fold) than human insulin in inhibiting the binding of [I-125-Tyr-A14] insulin to the soluble full-length recombinant human insulin receptor, which is probably a consequence of the substitution (Thr --> Kis) at position A-8. Bufo glucagon was isolated in two molecular forms: glucagon-29 shows only one amino acid substitution (Thr29 --> Ser), compared with human glucagon; and glucagon-36 comprises glucagon-29, extended from its C-terminus by Lys-Arg-Ser-Gly-Gly-Met-Ser. The human proglucagon gene contains one copy of glucagon-like peptide (GLP)-1, a potent insulin secretogogue, and one copy of GLP-2 that is devoid of insulin-releasing activity. In contrast, two proglucagon-derived peptides with 32- and 37-amino acid residues (GLP-32 and GLP-37), displaying greater structural similarity to human GLP-1 than to GLP-2, were isolated from Bufo pancreas. Both peptides produced concentration-dependent increases in insulin release from glucose-responsive rat insulinoma-derived BRIN-BD11 cells. The threshold concentrations producing a significant (P < 0.001) effect were 10(-8) M (GLP-32) and 10(-9) M (GLP-37), and the maximum increase in the rate of insulin release produced by 10(-6) M concentrations of both peptides was approximately 5-fold.

AB - Insulin and four peptides derived from the posttranslational processing of proglucagon have been isolated in pure form from the pancreas of the cane toad, Bufo marinus. Although Bufo insulin contains 9 amino acid substitutions, compared with human insulin, all those residues that are considered to be involved in receptor-binding and in dimer and hexamer formation have been conserved. Bufo insulin was, however, more potent (4-fold) than human insulin in inhibiting the binding of [I-125-Tyr-A14] insulin to the soluble full-length recombinant human insulin receptor, which is probably a consequence of the substitution (Thr --> Kis) at position A-8. Bufo glucagon was isolated in two molecular forms: glucagon-29 shows only one amino acid substitution (Thr29 --> Ser), compared with human glucagon; and glucagon-36 comprises glucagon-29, extended from its C-terminus by Lys-Arg-Ser-Gly-Gly-Met-Ser. The human proglucagon gene contains one copy of glucagon-like peptide (GLP)-1, a potent insulin secretogogue, and one copy of GLP-2 that is devoid of insulin-releasing activity. In contrast, two proglucagon-derived peptides with 32- and 37-amino acid residues (GLP-32 and GLP-37), displaying greater structural similarity to human GLP-1 than to GLP-2, were isolated from Bufo pancreas. Both peptides produced concentration-dependent increases in insulin release from glucose-responsive rat insulinoma-derived BRIN-BD11 cells. The threshold concentrations producing a significant (P < 0.001) effect were 10(-8) M (GLP-32) and 10(-9) M (GLP-37), and the maximum increase in the rate of insulin release produced by 10(-6) M concentrations of both peptides was approximately 5-fold.

M3 - Article

VL - 139

SP - 3442

EP - 3448

JO - Endocrinology

T2 - Endocrinology

JF - Endocrinology

SN - 0013-7227

IS - 8

ER -