Genentech, Inc.

Other

Herman A De Boer

Peter H Seeburg

Herbert L Heyneker

Herbert L Heynerer

High-level expression of bovine growth hormone is achieved using DNA encoding bovine growth hormone which, when transcribed, produces messenger RNA (mRNA) that at its 5' end is substantially free of secondary structure that is capable of interfering with translation of the mRNA.

DNA for expression of bovine growth hormone

Expression levels of polypeptides in recombinant host cell culture are increased by the use of synthetic DNA sequences chosen so that the mRNA transcribed therefrom is free of secondary structure sufficient to interfere with the efficiency of mRNA translation.

Methods and products for facile microbial expression of DNA sequences

Microbial expression of an exogenous polypeptide may be inefficient if the messenger RNA has secondary structure (due to complementarity of spaced regions of the molecule) which impedes interaction with a ribosome. The occurrence of such structure can be predicted. The degeneracy of the genetic code gives freedom to alter the nucleic acid composition of the CDNA to eliminate harmful secondary structure of the MRNA. For example, bovine growth hormone (BGH) is poorly expressed by E. coli transformed with a recombinant plasmid containing the natural BGH gene. The corresponding MRNA has complementary regions at 46-51 and 73-78. Therefore a plasmid PBGH 33-4 was constructed containing a BGH gene whose upstream portion was synthesized (making use of plasmid PHGH 207-1 which contains an efficiently expressible gene for the closely related human growth hormone) so as not to cause the troublesome complementarity. E. coli transformed therewith produced BGH with-a yield of better than 10.sup.5 copies per cell.

Method for expression of bovine growth hormone

Novel amino terminal methionyl embodiments of bovine growth hormone are prepared in recombinant cell culture. Amino terminal methionyl derivatives of bovine growth hormone are particularly useful in enhancing milk production by dairy cattle.

Terminal methionyl bovine growth hormone and its use

A method is described that dedicates specialized ribosomes to the synthesis of desired proteins. DNA which encodes rRNA having a mutant anti-Shine-Dalgarno sequence is used to transform a host cell in combination with DNA encoding messsenger RNA for the desired protein having a complementary mutant Shine-Dalgarno sequence. Since the mutant sequences are selected so as to be substantially unrecognized by either endogenous messenger RNA or ribosomes, respectively, the synthesis of protein proceeds in a dedicated system without interference from other host cell protein synthetic machinery.

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Pacifica, CA, United States of America

Herman A De Boer