Crystallization and preliminary crystallographic data of the alpha-amylase inhibitors, Haim I and Paim I.
Two proteins that act as alpha-amylase inhibitors, Haim I and Paim I, were crystallized and preliminary X-ray diffraction studies on them were carried out. We also sequenced Haim I prepared from Streptomyces griseosporeus YM-25 and confirmed that it is composed of 78 amino acid residues. Crystals of Haim I were grown from ammonium sulfate solution mixed with ethanol by the vapor diffusion technique. The crystals grew as hexagonal bipyramids and diffracted X-rays beyond 2.0 A resolution. They belong to the space group P6(1)22 (or P6(5)22) with unit cell dimensions of a = b = 36.7 A, c = 192.4 A, and contain one molecule per asymmetric unit. Paim I, a protein of 39 amino acid residues produced by Streptomyces corchorusii, was crystallized under similar conditions to Haim I. The crystals diffracted X-rays beyond 2.5 A. They belong to the space group P4(1)2(1)2 (or P4(3)2(1)2) with unit cell dimensions of a = b = 65.4 A, c = 96.1 A, and contain three molecules per asymmetric unit.
Miyagawa
M
M
Protein Engineering Research Institute, Osaka.
Fukuhara
K
K
Katayanagi
K
K
Ishimaru
K
K
Morikawa
K
K
Matsuzaki
T
T
Sato
Y
Y
Hara
S
S
Ikenaka
T
T
Arai
M
M
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D013302:Streptomyces / Q000737:chemistry; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
D001426:Bacterial Proteins; C087320:HAIM I protein, Streptomyces griseosporeus; D010455:Peptides; C054616:Paim I; D000516:alpha-Amylases