Crystallization and preliminary X-ray diffraction analysis of HeLp, a heme lipoprotein from the hemolymph of the cattle tick Boophilus microplus.
The main protein present in the hemelymph of the cattle tick Boophilus microplus is a lipoprotein able to bind heme (HeLp). It has an apparent molecular weight of 354 000 Da and is composed of two polypeptide chains found in stoichiometric amounts. It contains 33% lipids. The protein was crystallized using the hanging-drop vapour-diffusion method in the presence of 1,6-hexanediol as a precipitant. X-ray diffraction data were collected to 2.1 A resolution using a synchrotron-radiation source. The crystal belongs to the triclinic space group P1, with unit-cell parameters a = 90.58, b = 105.50, c = 116.14 A, alpha = 112.40, beta = 111.64, gamma = 91.35 degrees. Owing to the lack of information about the amino-acid sequence, the structure of HeLp will be solved by the use of heavy atoms. Several possible derivatives have been collected and analysis is under way.
Alves
Liliane Rosa
LR
Departamento de Bioquímica Médica, Instituto de Ciências Biomédicas, Universidade Federal de Rio de Janeiro, Rio de Janeiro, Brazil.
Oliveira
Pedro Lagerbald
PL
Barbosa
João Alexandre Ribeiro Gonçalves
JA
Guimarães
Beatriz Gomes
BG
Medrano
Francisco Javier
FJ
D000818:Animals; D001059:Apoproteins / Q000737:chemistry; D001798:Blood Proteins / Q000737:chemistry*; D002417:Cattle; D003460:Crystallization; D003627:Data Interpretation, Statistical; D006458:Hemolymph / Q000737:chemistry*; D008970:Molecular Weight; D011485:Protein Binding; D011487:Protein Conformation; D013987:Ticks / Q000737:chemistry*; D014961:X-Ray Diffraction
D001059:Apoproteins; D001798:Blood Proteins