The structure, stability, and complex behavior of recombinant human gelatins.
Gelatin prepared from animal sources is widely used as a stabilizer in vaccine formulations. The disadvantages associated with their use such as heterogeneity and allerginicity, have led to the development of recombinant human gelatins (rhGs) as a substitute. This study focuses on characterizing the structure and monitoring the physical stability of four molecular weights ( approximately 8.5, 25, 50, and 100 kDa) of rhGs as a function of temperature and pH. The information supplied should be useful in predicting the behavior of rhGs under formulation conditions. A number of spectroscopic techniques were employed in this study. Experimental results indicated that the solution properties of all four rhGs were unpredictable with micro-aggregation observed at various pH values. The 8.5 kDa rhG was found to be in a micro-aggregated state at pH 5 while the 25 kDa rhG was found to be more aggregated at pHs 5, 7, and 8. The properties of these aggregates have been analyzed as a function of temperature. The rhGs were also found to complex with the polyanion heparin through electrostatic and nonelectrostatic interactions. The stability of these complexes has been studied as a function of temperature and pH.
Thyagarajapuram
Nagarajan
N
Department of Pharmaceutical Chemistry, University of Kansas, 2030 Becker Drive, Lawrence, KS 66049, USA.
Olsen
David
D
Middaugh
C Russell
CR
D002626:Chemistry, Pharmaceutical; D002942:Circular Dichroism; D004339:Drug Compounding; D005079:Excipients / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry*; D006493:Heparin / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D011487:Protein Conformation; D011489:Protein Denaturation; D011994:Recombinant Proteins / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013678:Technology, Pharmaceutical / Q000379:methods; D013696:Temperature
D005079:Excipients; D011994:Recombinant Proteins; D005780:Gelatin; D006493:Heparin