| Abstrakt: |
A calcium-binding protein from porcine intestinal mucosa has been characterized by a variety of physical and chemical techniques. Chromatography on Sephadex G-75 suggests a molecular weight around 12,000, while electrophoresis in sodium dodecyl sulfate-urea-polyacrylamide gel indicates a molecular weight in the region of 7000. Sedimentation equilibrium analyses give evidence for aggregation, with the monomeric form having a molecular weight between 7000 and 9000. The amino acid composition is as follows: Lys11–12, Arg1, Asp7, Thr1, Ser6–7, Glu17, Gly4, Ala5, Val3, Ile3, Leu10, Tyr1, Phe5. There is no histidine, half-cystine, methionine, or tryptophan. The composition requires a minimal molecular weight of 9000. No free terminal amino group was detectable, but digestion with penicillocarboxypeptidases S1 and S2 indicated the following COOH-terminal sequence: .... (Gly, Thr, Asp)Ala-Ile-Val(Phe, Ser)Leu-Lys-GlnOH. |
