Evaluation of the C-terminal C5a effector site with short synthetic C5a analog peptides
| Autor: | Jörg Köhl, Wilfried Bautsch, Andreas Klos, Monika Casaretto, Bettina Lübbers |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Blood Platelets
Neutrophils Molecular Sequence Data Immunology Complement C5a Peptide In Vitro Techniques Biology Guinea pig Structure-Activity Relationship Adenosine Triphosphate Acetylglucosaminidase Tumor Cells Cultured Animals Humans Immunology and Allergy Potency Anaphylatoxin Amino Acid Sequence Peroxidase chemistry.chemical_classification Effector Biological activity Recombinant Proteins Enzyme assay Rats Amino acid chemistry Biochemistry biology.protein |
| Zdroj: | European Journal of Immunology. 23:646-652 |
| ISSN: | 1521-4141 0014-2980 |
| Popis: | Biological activities have been determined for a series of 18 peptides based on the C-terminal sequence of human or rat C5a. Lysosomal enzyme release was tested in two cell types, the promyelotic leukemia cell line U937 and polymorphonuclear leukocytes. In addition, an ATP-release assay with guinea pig platelets was performed. It was demonstrated that the C-terminal octapeptide 67-74 of human C5a represents the minimal sequence required to induce a measurable biological signal in all assays. Extending this peptide to a length of 21 amino acids produced at best only a slight enhancement of potency. Amino acid replacements with either tryptophanyl or phenylalanyl residues in positions between 65-69 either increased potency (at position 67), or abrogated potency (at position 66) in the two lysosomal enzyme assays. N-terminal acylation with the fluorenylmethoxy-carbonyl-aminohexanoyl group slightly enhanced C5a potency. In desensitization experiments with guinea pig platelets all peptides with a C5a activity were able to desensitize not only the C5a but also the C3a responses. |
| Databáze: | OpenAIRE |
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