Molecular characterization of human complement factor B subtypes

✍ Scribed by Christian Davrinche; Michel Abbal; André Clerc

• Book ID: 104666762
• Publisher: Springer-Verlag
• Year: 1990
• Tongue: English
• Weight: 366 KB
• Volume: 32
• Category: Article
• ISSN: 0093-7711
• DOI: 10.1007/bf00211644

✦ Synopsis

While several laboratories have agreed that there are two subtypes of the BF*F alleles, no information has been available until now at the molecular level. The region of the BF gene corresponding to the Ba fragment [1.7 kilobases (kb)] of the BF*S, BF*FA, and BF*FB alleles has been sequenced after specific amplification using the polymerase chain reaction (PCR). A point mutation at codon 7 has been revealed converting a cytosine in the BF*S allele to a thymidine in BF*FB. At the translational level an arginine residue in BF*S is substituted for a tryptophan residue in BF*FB. The amino-terminal sequencing of factor B immunoprecipitated from serum has been carried out from microquantities of protein blotted onto polyvinylidene fluoride (PVDF) membranes. We have shown that the difference between the BF*FA and the BF*FB subtypes in characterized by a glutamine at position 7 in BF*FA and a tryptophan in BF*FB.