EVIDENCE FOR THE PRESENCE OF A LARGE KERATAN SULFATE PROTEOGLYCAN IN THE HUMAN UTERINE CERVIX

Profound changes occur in the uterine cervix during pregnancy. In part icular, the extracellular matrix of the connective tissue is remodelle d extensively. To elucidate the mechanisms involved in this process, w e have analysed the proteoglycan pattern in the human cervix from preg nant and non-pregnant women. Proteoglycans of the cervix tissue specim en were extracted with 4 M guanidine hydrochloride and precipitated wi th 80% ethanol. Purification of proteoglycans was performed by several chromatographic steps. Characterization of proteoglycans was done by SDS/PAGE before and after digestion with glycosaminoglycan-specific en zymes. Proteoglycans were detected by combined Alcian Blue/silver stai ning or, after blotting of biotin-labelled proteoglycans on to poly(vi nylidene difluoride) membrane, with peroxidase-conjugated avidin or by the use of keratan sulphate- or decorin-specific monoclonal antibodie s. In contrast with previous reports, where only chondroitin/dermatan sulphate proteoglycans have been found in the uterine cervix, we have shown in the present study the existence of a large keratan sulphate p roteoglycan with an M(r) > 220000 in cervix samples from non-pregnant and pregnant women. This proteoglycan showed a strong reaction with th e keratan sulphate-specific monoclonal antibody 5D4 and could be degra ded by keratanases. The size of the core protein of this keratan sulph ate proteoglycan was estimated to be about M(r) 220000.