Human class 1 heparin-binding growth factor: structure and homology to bovine acidic brain fibroblast growth factor

Abstract

The structure of the major class 1 heparin-binding growth factor from human brain has been analyzed. Edman degradation performed on the native mitogen and on fragments generated by chemical and enzymatic cleavage allows the sequence to be described by four nonoverlapping segments. The sum of the amino acids of the four segments is in excellent agreement with the experimentally determined amino acid composition of the mitogen itself, suggesting that, jointly, they account for the entire molecule. The four segments can be aligned into a presumptive complete sequence that shows 92% identity with that of bovine acidic brain fibroblast growth factor. The data indicate that the human mitogen has the following sequence: Phe1-Asn-Leu-Pro-Pro-Gly-Asn-Tyr-Lys-Lys-Pro-Lys-Leu-Leu-Tyr15-Cys-Ser-Asn-Gly-Gly-His-Phe-Leu-Arg-Ile-Leu-Pro-Asp-Gly-Thr30-Val-Asp-Gly-Thr-Arg-Asp-Arg-Ser-Asp-Gln-His-Ile-Gln-Leu-Gln45-Leu-Ser-Ala-Glu-Ser-Val-Gly-Glu-Val-Tyr-Ile-Lys-Ser-Thr-Glu60-Thr-Gly-Gln-Tyr-Leu-Ala-Met-Asp-Thr-Asp-Gly-Leu-Leu-Tyr-Gly75-Ser-Gln-Thr-Pro-Asn-Glu-Glu-Cys-Leu-Phe-Leu-Glu-Arg-Leu-Glu90-Glu-Asn-His-Tyr-Asn-Thr-Tyr-Ile-Ser-Lys-Lys-His-Ala-Glu-Lys105-Asn-Trp-Phe-Val-Gly-Leu-Lys-Lys-Asn-Gly-Ser-Cys-Lys-A rg-Gly120-Pro-Arg-Thr-His-Tyr-Gly-Gln-Lys-Ala-Ile-Leu-Phe-Leu-Pro-Leu135-Pro-Val-Ser-Ser-Asp140.