Mink growth hormone structural-functional relationships: effects of renaturing and storage conditions.
Fourier-transform infrared spectroscopy, in vitro bioassay and enzyme-linked immunoassay were used to study the structural-functional relationships of recombinant mink growth hormone (mGH), refolded and stored under different conditions. Porcine GH (pGH) was synthesized and used as an example. These two hormones, when refolded and stored the same way, had the same secondary structures, biological and immunological efficacy, and biological potency. Only the immunological potency differed, mGH being significantly less potent than pGH. Renaturation pH and storing frozen or at 4 degrees C in 5% glycerol did not affect either the secondary structure or the activity. However, freeze-drying raised the content of buried alpha-helices and lowered that of solvated alpha-helices and of unordered structures. These conformational changes were associated with a reduction of immunological and biological potency of mGH and of immunological potency of pGH. These findings provide original information on the secondary structure of mGH, and show that conformational changes induced by lyophilization adversely affect its activity.
Borromeo
Vitaliano
V
Department of Animal Pathology and Health, Faculty of Veterinary Medicine, University of Milan, Milan, Italy. vitaliano.borromeo@unimi.it
Sereikaite
Jolanta
J
Bumelis
Vladas-Algirdas
VA
Secchi
Camillo
C
Scirè
Andrea
A
Ausili
Alessio
A
D'Auria
Sabato
S
Tanfani
Fabio
F
D000595:Amino Acid Sequence; D000818:Animals; D045744:Cell Line, Tumor; D005612:Freeze Drying; D013006:Growth Hormone / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008907:Mink / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D020673:Protein Renaturation; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D016415:Sequence Alignment; D017550:Spectroscopy, Fourier Transform Infrared; D013329:Structure-Activity Relationship; D013552:Swine; D013696:Temperature
D011994:Recombinant Proteins; D013006:Growth Hormone