The human two domain trefoil protein, TFF2, is glycosylated in vivo in thestomach

Background-TFF2, a member of the tre-foil factor family (TFF) of peptides, is a secreted protein of 106 amino acids that is expressed in mucous neck c ells of the fundus and glands at the base of the antrum In normal human sto mach. TFF2 is also detected at high concentrations around sites of ulcerati on. It is protective against mucosal damaging agents and stimulates cell mo tility. Aims-To measure the expression of TFF2 in normal human stomach and its secr etion into gastric juice. Methods-TFF2 cDNA was amplified by reverse transcription polymerase chain r eaction from gastric mucose and sequenced. Gastric juice or cytosol, prepar ed from gastric mucosa, was obtained from individuals with macroscopically normal stomachs. TFF2 concentrations were measured by quantitative western transfer analysis. Results-Sequencing of TFF2 cDNA revealed a single amino acid change from th e published sequence. Significant: amounts of 12 kDa TFF2 were detected in human gastric juice. Larger quantities of a protein of higher apparent mole cular mass were also detected. This was shown to be N-glycosylated TFF2 usi ng the endoglycosidase, peptide-N-Gycosidase F. The majority of TFF2 in nor mal gastric mucosa was also glycosylated. Conclusion-Human TFF2 is glycosylated via an N-linkage, presumably on Asn'S 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 s equence. Biological studies should be performed with recombinant protein of the correct sequence, and the biological consequences of glycosylation inv estigated.