Dataset Information

Human Salivary Cystatins - SALIVARY CYSTATINS: EXPLORING NEW POST-TRANSLATIONAL MODIFICATIONS AND POLYMORPHISMS BY TOP-DOWN HIGH RESOLUTION MASS SPECTROMETRY

ABSTRACT: In the present study various proteoforms of cystatin A, cystatin B, cystatin D, cystatin S, cystatin SN and cystatin SA were detected and characterized by a top-down HPLC-ESI-MS platform integrated by bottom-up strategies in the acidic soluble fraction of human saliva. The several proteoforms derive from polymorphisms of the coding sequence and post-translational modifications, typically phosphorylation, N-terminal processing, and oxidation. The protein species detected in saliva collected from healthy subjects were: (i) cystatin AT96→M and its acetylated derivative; (ii) cystatin B N-terminally acetylated and carboxymethylated at C3; (iii) N-terminally truncated cystatin D with the N-terminal Q converted to pyro-E and lacking the first 5 amino acid residues (pGlu-cystatin D Des1-5); (iv) N-terminally truncated forms of cystatin SN and SNP11→L lacking the first 4 amino acids (cystatin SN Des1-4 and cystatin SNP11→L Des1-4) and the first 7 amino acids (cystatin SN Des1-7 and cystatin SNP11→L Des1-7); (v) N-terminally truncated cystatin SA lacking the first 7 amino acids (cystatin SA Des1-7); (vi) oxidized derivatives of cystatins SN and S1 at W23 and W107.

INSTRUMENT(S): LTQ Orbitrap Elite

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Saliva

SUBMITTER: Barbara Manconi

LAB HEAD: Barbara Manconi

PROVIDER: PXD007170 | Pride | 2017-10-13

REPOSITORIES: Pride

ACCESS DATA

Publications

Salivary Cystatins: Exploring New Post-Translational Modifications and Polymorphisms by Top-Down High-Resolution Mass Spectrometry.

Manconi Barbara B Liori Barbara B Cabras Tiziana T Vincenzoni Federica F Iavarone Federica F Castagnola Massimo M Messana Irene I Olianas Alessandra A

Journal of proteome research 20171101 11

Cystatins are a complex family of cysteine peptidase inhibitors. In the present study, various proteoforms of cystatin A, cystatin B, cystatin S, cystatin SN, and cystatin SA were detected in the acid-soluble fraction of human saliva and characterized by a top-down HPLC-ESI-MS approach. Proteoforms of cystatin D were also detected and characterized by an integrated top-down and bottom-up strategy. The proteoforms derive from coding sequence polymorphisms and post-translational modifications, in ...[more]

PMID: 29019242

Similar Datasets

Project description:Due to the distinctive features of oral mucosa, determination of the proteins involved in the formation of “oral protein pellicle” is demanding. The present study investigated the susceptibility of several human basic proline-rich peptides (bPRPs) named P-H, P-D, P-F, P-J, and II-2 as substrates of transglutaminase-2. The reactivity of P-C peptide and statherin was also investigated. Peptides purified from human whole saliva were incubated at diverse temperatures with two different transglutaminases (type 2; guinea pig and human), in the presence or in the absence of monodansyl-cadaverine. High resolution HPLC-ESI-MS and MS/MS analyses of the reaction products highlighted that P-H, and P-D were active substrates of transglutaminase-2, II-2 was less reactive and the reactivity of P-F and P-J was negligible. All the peptides formed cyclo-derivatives, and only specific glutamine residues were involved in the cycle formation and reacted with monodansyl-cadaverine. Q29 for P-H, Q37 for P-D, and Q21 for II-2 were the principal reactive residues. One or two secondary glutamine residues were hierarchically susceptible to reaction with dansyl-cadaverine. The main consensus sequence recognized by transglutaminase-2 in basic proline-rich peptides was GNPQ, and, despite the great similarity of P-F and P-J with the other salivary peptides, their reactivity was negligible, probably because the GNPQ consensus sequence was missing in their sequence. The reactivity of P-D A32 variant was lower than that of P-D P32 peptide suggesting that the more rigid peptide structure was a better substrates for transglutaminase-2. The reactivity of P-C was high, but followed rules different from the other basic peptides under study, Q41 being the principal reactive residue, confirming that P-C is not strictly related to the basic proline-rich proteins. The reactivity of statherin was very high too, and the manual inspection of the MS/MS fragmentation patterns of the reaction products confirmed, as determined in previous studies, that Q37 is the pivotal residue, Q39 and Q40 the secondary residues recognized by transglutaminase-2. Moreover, Q39 and Q40 residues were more reactive in cyclo-statherin Q37 than in statherin, suggesting that cycle formation increases the reactivity of the secondary glutamine residues. Finally, the physiological temperature (37°C) was the best for the reaction and no significant qualitative differences were observed using human or guinea pig transglutaminase-2.

Dataset Information

Human Salivary Cystatins - SALIVARY CYSTATINS: EXPLORING NEW POST-TRANSLATIONAL MODIFICATIONS AND POLYMORPHISMS BY TOP-DOWN HIGH RESOLUTION MASS SPECTROMETRY

Publications

Salivary Cystatins: Exploring New Post-Translational Modifications and Polymorphisms by Top-Down High-Resolution Mass Spectrometry.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure