ble dating lesson online study - Map 2983

Sequencing primers were synthesized to extend sequence readings using an Applied Biosystems 381A DNA synthesizer.Each sequence was determined at least twice from both strands. Map 2983-33

The three diagnostic residues that are completely conserved among all Bf and C2 are indicated by ∗.

The first residue of Hr1 is shown here as F; however, the amino acid at this position deduced from a full-length c DNA clone was V.

This discrepancy was due to the fact that the first two nucleotides encoding this amino acid of the RT-PCR product had originated from the 5′ primer, and the template sequence contained a mismatch at the first nucleotide (see text).

DNA sequence analysis was performed by the dideoxy chain termination method (16) using an Applied Biosystems 373A DNA sequencer.

The activated MASP then activates the classical pathway by proteolytically cleaving C4 and C2.

MBP and MASP show structural similarity to C1q and C1r/C1s, respectively, indicating that gene duplication events were also responsible for generating the classical and lectin pathways.

Surprisingly, neither clone is related to Bf/C2 but rather share the same domain structure of mammalian C1r/C1s/MASP (mannan binding protein-associated serine protease), and are more related evolutionarily to mammalian MASP than to mammalian C1r or C1s.

The identification of the tunicate MASP clones, amplified with primers designed to amplify Bf or C2, suggests that the lectin pathway antedated the classical and alternative pathways of complement activation.

Two different clones were isolated and designated Hr1 and Hr2.

The deduced amino acid sequences of these clones were aligned with the corresponding regions of human Bf (Hu Bf) and C2 (Hu C2).

Identification of MASP in tunicates suggests that the lectin pathway was the original mechanism for activation of the complement system. The hepatopancreas was removed from dissected ascidians immediately before use.

Tags: , ,