CRYSTALLIZATION AND INITIAL X-RAY-ANALYSIS OF BETA-CRUSTACYANIN, THE DIMER OF APOPROTEINS A(2) AND C-1, EACH WITH A BOUND ASTAXANTHIN MOLECULE

Crystals of beta-crustacyanin, a carotenoid-binding protein from lobst er carapace, have been grown under oil from solutions containing sodiu m potassium phosphate as precipitant. They grow slowly over a period o f months to reach maximal dimensions of 0.5 x 0.1 x 0.1 mm, and belong to space group P622 with cell dimensions: a = b = 124.39, c = 188.86 Angstrom and gamma 120 degrees. The crystals diffract to beyond 3 Angs trom but are very radiation sensitive, limiting the resolution of usab le data. The unit-cell volume suggests that there are two beta-crustac yanin molecules per asymmetric unit.