title: Top-down HPLC-ESI-MS detection of S-glutathionylated and S-cysteinylated derivatives of cystatin B and its 1-53 and 54-98 fragments in whole saliva of human preterm newborns.
abstract: Analysis by a HPLC-ESI-MS top-down proteomic platform of specimens of human preterm newborn whole saliva evidenced high relative amounts of cystatin B and its S-glutathionylated,S-cysteinylated, and S-S 2-mer (on Cys(3)) derivatives, decreasing as a function of postconceptional age (PCA). The percentage of S-unmodified cystatin B was higher than the S-modified isoforms in the early PCA period, differently from adults where cystatin B was detectable only as S-modified derivatives. The percentage of S-modified derivatives increased as a function of PCA, reaching at the normal term of delivery values similar to those determined in at-term newborns, babies, and adults. Moreover, in the early PCA period, high relative amounts of the 1-53 and 54-98 cystatin B fragments were detected, decreasing as a function of PCA and disappearing at the normal term of delivery. In agreement with intact cystatin B, fragment 1-53 was detectable as S-unmodified and S-modified derivatives, and their percentages changed accordingly with the percentages of intact proteins, suggesting that the fragmentation process could be subsequent to and independent from the S-modification of the protein. This study highlights specific enzymatic activity in the oral cavity of preterm newborns not present in at-term newborns and adults, which can be a clue to specialized pathways occurring during fetal oral development.
authors.affiliation: Istituto di Biochimica e di Biochimica Clinica, Università Cattolica and/or Istituto per la Chimica del Riconoscimento Molecolare, CNR, Istituto Scientifico Internazionale (ISI) Paolo VI, Roma, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Iavarone
authors.forename: Tiziana
authors.initials: T
authors.lastname: Cabras
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Pisano
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Sanna
authors.forename: Sonia
authors.initials: S
authors.lastname: Nemolato
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vento
authors.forename: Chiara
authors.initials: C
authors.lastname: Tirone
authors.forename: Costantino
authors.initials: C
authors.lastname: Romagnoli
authors.forename: Massimo
authors.initials: M
authors.lastname: Cordaro
authors.forename: Vassilios
authors.initials: V
authors.lastname: Fanos
authors.forename: Gavino
authors.initials: G
authors.lastname: Faa
authors.forename: Irene
authors.initials: I
authors.lastname: Messana
authors.forename: Massimo
authors.initials: M
authors.lastname: Castagnola
mesh_terms: D000328:Adult; D002851:Chromatography, High Pressure Liquid; D055313:Cystatin B / Q000032:analysis* / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism*; D005260:Female; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000737:chemistry; D010446:Peptide Fragments / Q000032:analysis*; D012463:Saliva / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: C524994:CSTB protein, human; D010446:Peptide Fragments; D055313:Cystatin B; D005978:Glutathione; D003545:Cysteine