“Of peptides that strongly inhibit tubulin polymerization (… 10 isomers, segments, and analogs, dolastatin 15 , and phomopsin A), only those previously shown to be … vinblastine binding and nucleotide exchange also strongly inhibited [3H]dolastatin 10 binding and induced tubulin aggregation (dolastatin 10 itself, … isomers of dolastatin 10, and phomopsin A).”