Characterization of two isoforms of human SPRR3 from saliva of preterm human newborn and autoptic fetal oral mucosa, parotid and submandibular gland samples.
RP-HPLC-ESI-MS profile of saliva samples from human preterm newborn showed a protein peak in the elution range 26.6-27.6min. Deconvolution of ESI-MS spectra revealed the presence of two proteins with average molecular mass (Mav) values of 17,239+/-3Da and 18,065+/-3Da in 9 samples, with Mav value of 17,239+/-3Da in 4 samples and Mav value of 18,065+/-3Da in 2 samples. MALDI-TOF-MS analysis of tryptic digest allowed identifying the proteins as two isoforms of small proline-rich protein 3 and cDNA amplification of RNA extracts from oral mucosa, parotid and submandibular gland samples, obtained at fetal autopsy, provided two nucleotide sequences in agreement with those reported in the literature. The two proteins differ for an octapeptide repeat (GCTKVPEP) and the substitution Leu-->Val, at position 148 and 140 of the mature form of the 18,065 and 17,239Da protein, respectively. During maturation the two proteins undergo two post-translational modifications, corresponding to N-terminal acetylation and removal of the initiator methionine. cDNA amplification did not allow to clarify if the proteins found in saliva originated from cellular shedding of the epithelium and/or secretion.
Manconi
Barbara
B
Dipartimento di Scienze Applicate ai Biosistemi, Università di Cagliari, Cittadella Universitaria, I-09042 Monserrato (CA), Italy.
Cabras
Tiziana
T
Pisano
Elisabetta
E
Nemolato
Sonia
S
Inzitari
Rosanna
R
Iavarone
Federica
F
Fanali
Chiara
C
Sanna
Maria Teresa
MT
Tirone
Chiara
C
Vento
Giovanni
G
Romagnoli
Costantino
C
Faa
Gavino
G
Castagnola
Massimo
M
Messana
Irene
I
D002851:Chromatography, High Pressure Liquid; D055233:Cornified Envelope Proline-Rich Proteins / Q000737:chemistry* / Q000235:genetics; D005333:Fetus / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D009061:Mouth Mucosa / Q000196:embryology / Q000378:metabolism*; D010306:Parotid Gland / Q000196:embryology / Q000378:metabolism*; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D012463:Saliva / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D013363:Submandibular Gland / Q000196:embryology / Q000378:metabolism*
D055233:Cornified Envelope Proline-Rich Proteins; D020033:Protein Isoforms; C112254:SPRR3 protein, human