Crystallization and preliminary X-ray analysis of carnein, a serine protease from Ipomoea carnea.
Carnein is an 80 kDa subtilisin-like serine protease from the latex of the plant Ipomoea carnea which displays an exceptional resistance to chemical and thermal denaturation. In order to obtain the first crystal structure of a plant subtilisin and to gain insight into the structural determinants underlying its remarkable stability, carnein was isolated from I. carnea latex, purified and crystallized by the hanging-drop vapour-diffusion method. A data set was collected to 2.0 A resolution in-house from a single crystal at 110 K. The crystals belonged to the trigonal space group P3(1)21 or P3(2)21, with unit-cell parameters a = b = 126.9, c = 84.6 A, alpha = beta = 90, gamma = 120 degrees. Assuming the presence of one molecule per asymmetric unit, the Matthews coefficient is 2.46 A(3) Da(-1), corresponding to a solvent content of 50%. Structure determination of the enzyme is in progress.
Patel
Ashok Kumar
AK
Molecular Biology Unit, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India.
van Oosterwijk
Niels
N
Singh
Vijay Kumar
VK
Rozeboom
Henriëtte J
HJ
Kalk
Kor H
KH
Siezen
Roland J
RJ
Jagannadham
Medicherla V
MV
Dijkstra
Bauke W
BW