Purification, Crystal
Growth and Preliminary X-ray Analysis of a Phospholipase A2 from
Venom of Agkistrondon acutus
ZHANG Hai-Long, LIN Zheng-Jiong*
( National Laboratory of Biomacromolecules, Institute of Biophysics,
Academia Sinica, Beijing 100101, China )
DU Xiao-Yan, ZHOU Yuan-Cong
( Shanghai Institute of Biochemistry, the Chinese Academy of Science,
Shanghai 200031, China )
Abstract An acidic
phospholipase A2 from Agkistrondon acutus venom has been
purified to homogeneity via four steps using CM-Sepharose, two times
DEAE-Sepharose, and Mono Q FPLC. The molecular weight of the protein was about
16.5 kD and the isoelectric point was 4.3. The purified enzyme showed a potent
inhibitory effect on platelet aggregation induced by ADP in human
platelet-enriched plasma. The enzyme was then crystallized by hanging drop
diffusion method using 2-methyl-2,4-pentanediol as a precipitant. Two kinds of
single crystals suitable for X-ray crystallographic studies were obtained.
X-ray crystallographic analysis showed that both crystal forms belong to
monoclinic system and space group P21. The cell dimensions of form I crystals
were a = 43.48 Å, b = 71.49 Å, c = 43.85 Å and β =
116.32°；
Those of form II crystals were a = 49.25 Å, b = 38.33 Å, c
= 70.25 Å and β = 99.20°. Complete diffraction data sets have been collected to
medium resolution for the two crystal forms.
Key words phospholipase A2； Agkistrodon acutus； purification； crystallization； preliminary X-ray analysis
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