De novo sequencing of two novel peptides homologous to calcitonin-like peptides, from skin secretion of the Chinese Frog, Odorrana schmackeri

Evaristo, G.P.C.; Pinkse, M.W.H.; Chen, T.; Wang, L.; Mohammed, S.; Heck, A.J.R.; Mathes, I.; Lottspeich, F.; Shaw, C.; Albar, J.P.; Verhaert, P.D.E.M.

doi:doi:10.1016/j.euprot.2015.07.008

De novo sequencing of two novel peptides homologous to calcitonin-like peptides, from skin secretion of the Chinese Frog, Odorrana schmackeri

Title

De novo sequencing of two novel peptides homologous to calcitonin-like peptides, from skin secretion of the Chinese Frog, Odorrana schmackeri

Author

Evaristo, G.P.C.
Pinkse, M.W.H.
Chen, T.
Wang, L.
Mohammed, S.
Heck, A.J.R.
Mathes, I.
Lottspeich, F.
Shaw, C.
Albar, J.P.
Verhaert, P.D.E.M.

Faculty

Applied Sciences

Department

BT/Biotechnology

Date

2015-07-06

Abstract

An MS/MS based analytical strategy was followed to solve the complete sequence of two new peptides from frog (Odorrana schmackeri) skin secretion. This involved reduction and alkylation with two different alkylating agents followed by high resolution tandem mass spectrometry. De novo sequencing was achieved by complementary CID and ETD fragmentations of full-length peptides and of selected tryptic fragments. Heavy and light isotope dimethyl labeling assisted with annotation of sequence ion series. The identified primary structures are GCD[I/L]STCATHN[I/L]VNE[I/L]NKFDKSKPSSGGVGPESP-NH2 and SCNLSTCATHNLVNELNKFDKSKPSSGGVGPESF-NH2, i.e. two carboxyamidated 34 residue peptides with an aminoterminal intramolecular ring structure formed by a disulfide bridge between Cys2 and Cys7. Edman degradation analysis of the second peptide positively confirmed the exact sequence, resolving I/L discriminations. Both peptide sequences are novel and share homology with calcitonin, calcitonin gene related peptide (CGRP) and adrenomedullin from other vertebrates. Detailed sequence analysis as well as the 34 residue length of both O. schmackeri peptides, suggest they do not fully qualify as either calcitonins (32 residues) or CGRPs (37 amino acids) and may justify their classification in a novel peptide family within the calcitonin gene related peptide superfamily. Smooth muscle contractility assays with synthetic replicas of the S–S linked peptides on rat tail artery, uterus, bladder and ileum did not reveal myotropic activity.

Subject

calcitonin-like peptides
CGRP-like peptides
adrenomedullin-like peptides
frog skin
LC MSn
de novo sequencing

To reference this document use:

http://resolver.tudelft.nl/uuid:fbc19924-21b0-42f6-998f-3bc339d51a71

Publisher

Elsevier

ISSN

2212-9685

Source

https://doi.org/10.1016/j.euprot.2015.07.008

Source

EuPA Open Proteonomics, 8, 2015