Purification, crystallization and preliminary X-ray investigation of aqualysin I, a heat-stable serine protease.
Aqualysin I, a thermostable protease found in the culture medium of Thermus aquaticus YT-1, has been purified to homogeneity using a combination of ion-exchange and affinity chromatography. It is a polypeptide with a molecular weight of 28 350 [Kwon, Terada, Matsuzawa & Ohta (1988). Eur. J. Biochem. 173, 491-497] and is most active at 343-353 K and pH about 10.0 [Matsuzawa, Tokugawa, Hamaoki, Mizoguchi, Taguchi, Terada, Kwon & Ohta (1988). Eur. J. Biochem. 171, 441-447]. Crystals of the enzyme are monoclinic, space group P2(1), with cell dimensions a = 40.80 (5), b = 64.39 (6), c = 45.51 (6) A and beta = 109.1 (1) degrees. The asymmetric unit consists of a single molecule (V(m) = 1.99 A(3)Da(-1)). The crystals are stable to X-radiation and scatter to at least 2.8 A resolution.
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The Proctor & Gamble Company, Miami Valley Laboratories, Cincinnati, Ohio 45239-8707, USA.
Oliver
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Strickland
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Toerner
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Matsuzawa
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Ohta
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