Mutant fibroblast growth factor (FGF) proteins having a polypeptide sequence with a high sequence identity to proteins encoded by members of the Fgf-1 subfamily of genes from a mammalian species, such as human, and with a specific amino acid substitution of an alanine at a position corresponding to amino acid position 66 of human FGF-1 with a cysteine and/or a specific amino acid substitution of a phenylalanine at a position corresponding to amino acid position 132 of human FGF-1 with a tryptophan (based on the 140 amino acid numbering scheme of human FGF-1) are provided. Other amino acid mutations or substitutions may be combined. Polynucleotide sequences encoding the mutant FGF proteins and host cells containing such polynucleotide sequences are provided. Methods of administering a mutant FGF protein to an individual to treat an ischemic condition or disease or a wound or tissue injury are also provided.