Biomedical Engineering Reference
In-Depth Information
Homogenization of
resuspended cell paste
E. coli fermentation
Centrifugaton
Polyethyleneimine
precipitation of
nucleic acid
Anion-exchange
chromatography
Ammonium sulphate
precipitation
Cation exchange
chromatography
Gel filtration
chromatography
Ammonium sulphate
precipitation
Figure 11.9 Production of rhGH in E. coli (as an intracellular protein). Subsequent to fermentation, the
cells are collected by centrifugation or fi ltration. After homogenization, nucleic acids and some membrane
constituents are precipitated by the addition of polyethyleneimine. Ammonium sulfate precipitation of the
supernatant concentrates the crude rhGH preparation. Chromatographic purifi cation follows, as illustrated
member of this family will adversely affect reproductive function, which generally can be treated
by administration of an exogenous preparation of the hormone in question. Most gonadotrophins
are synthesized by the pituitary, although some are made by reproductive and associated tissues.
11.5.1 Follicle-stimulating hormone, luteinizing hormone and human chorionic
gonadotrophin
FSH and LH play critical roles in the development and maintenance of male and, particularly,
female reproductive function (Box 11.3). hCG, produced by pregnant women, plays a central role
in maintaining support systems for the developing embryo during early pregnancy. All three are
Table 11.8 The gonadotrophins, their site of synthesis and their major biological effects
Gonadotrophin
Site of synthesis
Major effects
FSH
Pituitary
Stimulates follicular growth (female)
Enhanced spermatogenesis (male)
LH
Pituitary
Induction of ovulation (female)
Synthesis of testosterone (male)
CG
Maintenance of the corpus luteum in
pregnant females
PMSG (horses only)
Endometrial cups
Maintenance of pregnancy in equids
Inhibin
Gonads
Inhibition of FSH synthesis
Probably tumour repressor
Activin
Gonads
Stimulation of FSH synthesis
 
Search WWH ::




Custom Search