Amino acid sequence of horse colipase B.

The research paper discusses the determination of the complete amino acid sequence of horse colipase B, pointing out similarities and differences with other known sequences like horse colipase A or the pig cofactor.

Sequential Analysis of Horse Colipase B

The researchers used automated analysis on the intact protein and generated peptides using two different types of cleavage – CNBr and tryptic – to obtain the complete sequence of the 96 residues that make up horse colipase B.

• They found that the unique histidine of the protein is located at position 29, a sequence characteristic that mirrors that of horse colipase A.
• However, the position of histidine 86 in the pig cofactor, thought to play a crucial part in folding the molecule, is not conserved in horse colipase B.

Comparison between Pig and Horse B Chains

When comparing the horse B chains with pig chains, they found large sections to be either identical or very similar.

• This similarity was particularly noticeable in the N-terminal sequence and a central segment that extends from alanine at position 49 to cysteine at position 65. This segment encompasses all three tyrosines of the molecule.
• The four lysines and the ten half cystines are also conserved in the horse B sequence, in line with the comparisons made to the pig chains.

Conclusion

The findings contribute to the understanding of the amino acid structure of horse colipase B. This comprehensive sequence analysis allows for a comparative study with similar proteins like horse colipase A and the pig cofactor, potentially shedding light on structural and functional commonalities and differences. Clear identification of the amino acid sequence can support bioinformatics studies as well as veterinary and biomedical research involving these animal models.