RESUMO
Polymorphism in the Sp1 binding site in the first intron of the COL1A1 gene has been related to increased risk of osteoporosis in several populations. To overcome the difficulties associated with the use of mismatch oligonucleotide primers in the original method for its detection, we developed a procedure involving PCR amplification of a 598-base pair sequence from the intron and its digestion with the restriction enzyme Van 91 I. The more frequent allele is recognized by the enzyme, whereas the reaction is abolished in the less frequent allele. Two convenience samples from the population in northern Finland, consisting altogether of 173 individuals, were studied. The overall frequencies were 0.864 for the G and 0.136 for the T allele, with a heterozygocity of 27.2%. The frequency of the T allele is towards the lower end of the range observed for other European populations.
Assuntos
Colágeno Tipo I , Colágeno/genética , Reação em Cadeia da Polimerase/métodos , Polimorfismo Genético , Fator de Transcrição Sp1/genética , Alelos , Cadeia alfa 1 do Colágeno Tipo I , Primers do DNA/metabolismo , Feminino , Genótipo , Humanos , Masculino , Dados de Sequência MolecularRESUMO
Human C1 inhibitor is a highly glycosylated serine protease inhibitor of the serpin family. The protein contains two disulfide bonds. In this study, an N-terminally truncated form of recombinant C1 inhibitor was overexpressed in Escherichia coli strains BL21(DE3) and AD494(DE3), the latter enabling the formation of disulfide bonds within the cytoplasm. With both strains, a major fraction of the recombinant protein produced appeared to be insoluble. However, the soluble fraction of lysates from strain AD494(DE3) inhibited the C1s target protease in functional assays. Recombinant C1 inhibitor produced in this strain also displayed the ability to complex with C1s in vitro. In contrast, lysates from strain BL21(DE3) displayed no C1 inhibitor activity. These data support the notion that glycosylation is not important, whereas disulfide bond formation appears to be essential for the production of an active recombinant C1 inhibitor. Thus, bacterial strains that permit the formation of disulfide bonds may represent a reliable system for the production of recombinant C1 inhibitor. However, a major obstacle to large-scale production will be to produce the protein in a soluble form. Attempts to increase the yield of soluble protein by coexpression of the GroEL/ES chaperonins resulted in an increase in solubility.