BACKGROUNDTFF2, a member of the trefoil factor family (TFF) of peptides, is a secreted protein of 106 amino acids that is expressed in mucous neck cells of the fundus and glands at the base of the antrum in normal human stomach. TFF2 is also detected at high concentrations around sites of ulceration. It is protective against mucosal damaging agents and stimulates cell motility.
AIMSTo measure the expression of TFF2 in normal human stomach and its secretion into gastric juice.
METHODSTFF2 cDNA was amplified by reverse transcription polymerase chain reaction from gastric mucosa and sequenced. Gastric juice or cytosol, prepared from gastric mucosa, was obtained from individuals with macroscopically normal stomachs. TFF2 concentrations were measured by quantitative western transfer analysis.
RESULTSSequencing of TFF2 cDNA revealed a single amino acid change from the published sequence. Significant amounts of 12 kDa TFF2 were detected in human gastric juice. Larger quantities of a protein of higher apparent molecular mass were also detected. This was shown to be N-glycosylated TFF2 using the endoglycosidase, peptide-N-Gycosidase F. The majority of TFF2 in normal gastric mucosa was also glycosylated.
CONCLUSIONSHuman TFF2 is glycosylated via an N-linkage, presumably on Asn¹⁵ which forms part of the single consensus site for N-glycosylation in human TFF2. The glycosylation may be of functional significance. Future studies of human TFF2 should use antibodies raised against the correct amino acid sequence. Biological studies should be performed with recombinant protein of the correct sequence, and the biological consequences of glycosylation investigated.


Keywords: TFF peptide; stomach; glycosylation; TFF2; restitution