PURIFICATION AND BIOCHEMICAL-CHARACTERIZATION OF RECOMBINANT HUMAN PLACENTAL GROWTH-HORMONE PRODUCED IN ESCHERICHIA-COLI

Citation
A. Igout et al., PURIFICATION AND BIOCHEMICAL-CHARACTERIZATION OF RECOMBINANT HUMAN PLACENTAL GROWTH-HORMONE PRODUCED IN ESCHERICHIA-COLI, Biochemical journal, 295, 1993, pp. 719-724
Citations number
34
Categorie Soggetti
Biology
Journal title
ISSN journal
02646021
Volume
295
Year of publication
1993
Part
3
Pages
719 - 724
Database
ISI
SICI code
0264-6021(1993)295:<719:PABORH>2.0.ZU;2-#
Abstract
The hGH-V (or hGH-2) gene codes for human placental growth hormone (hP GH). Secretion of hPGH is continuous, in contrast with the pulsed secr etion of pituitary growth hormone (hGH) which it progressively replace s in the maternal bloodstream. hGH- V cDNA has previously been cloned and isolated. Analysis of its nucleotide sequence has revealed a 191-r esidue protein, hPGH, differing from hGH at 13 positions. The calculat ed pI is more basic than that of the pituitary hormone. Here we have i nserted hGH- VcDNA into the pIN-III-ompA3 plasmid in order to produce hPGH in its native form in Escherichia coli D1210. Expression of hGH- V cDNA in E. coli is significantly lower than that of hGH cDNA with th e same expression system. The hPGH produced in E. coli was purified in quantities sufficient to allow its biochemical and immunochemical cha racterization. The molecular mass of the protein was determined by ele ctrospray m.s. The determined mass, 22320 Da, agrees well with the mol ecular mass calculated from the translated cDNA sequence, assuming the presence of two disulphide bridges. Having established the technique for producing hPGH with a primary structure identical to the natural, non-glycosylated, 22 kDa isoform, we can now plan the full physicochem ical and pharmaceutical characterization of this new hormonal entity.