scholarly journals Spontaneous solubilization of membrane-bound human testis angiotensin-converting enzyme expressed in Chinese hamster ovary cells.

1991 ◽  
Vol 88 (3) ◽  
pp. 1009-1013 ◽  
Author(s):  
M. R. Ehlers ◽  
Y. N. Chen ◽  
J. F. Riordan
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Human Testis ◽  
Converting Enzyme ◽  
Ovary Cells ◽  
Membrane Bound

scholarly journals Shedding of somatic angiotensin-converting enzyme (ACE) is inefficient compared with testis ACE despite cleavage at identical stalk sites

2000 ◽  
Vol 347 (3) ◽  
pp. 711-718 ◽  
Author(s):  
Zenda L. WOODMAN ◽  
Sylvester Y. OPPONG ◽  
Sarah COOK ◽  
Nigel M. HOOPER ◽  
Sylva L. U. SCHWAGER ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Cleavage Site ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Analytical Techniques ◽  
Human Testis ◽  
Converting Enzyme ◽  
Substrate Preferences

The somatic and testis isoforms of angiotensin-converting enzyme (ACE) are both C-terminally anchored ectoproteins that are shed by an unidentified secretase. Although testis and somatic ACE both share the same stalk and membrane domains the latter was reported to be shed inefficiently compared with testis ACE, and this was ascribed to cleavage at an alternative site [Beldent, Michaud, Bonnefoy, Chauvet and Corvol (1995) J. Biol. Chem. 270, 28962-28969]. These differences constitute a useful model system of the regulation and substrate preferences of the ACE secretase, and hence we investigated this further. In transfected Chinese hamster ovary cells, human somatic ACE (hsACE) was indeed shed less efficiently than human testis ACE, and shedding of somatic ACE responded poorly to phorbol ester activation. However, using several analytical techniques, we found no evidence that the somatic ACE cleavage site differed from that characterized in testis ACE. First, anti-peptide antibodies raised to specific sequences on either side of the reported cleavage site (Arg1137/Leu1138) clearly recognized soluble porcine somatic ACE, indicating that cleavage was C-terminal to Arg1137. Second, a competitive ELISA gave superimposable curves for porcine plasma ACE, secretase-cleaved porcine somatic ACE (eACE), and trypsin-cleaved ACE, suggesting similar C-terminal sequences. Third, mass-spectral analyses of digests of released soluble hsACE or of eACE enabled precise assignments of the C-termini, in each case to Arg1203. These data indicated that soluble human and porcine somatic ACE, whether generated in vivo or in vitro, have C-termini consistent with cleavage at a single site, the Arg1203/Ser1204 bond, identical with the Arg627/Ser628 site in testis ACE. In conclusion, the inefficient release of somatic ACE is not due to cleavage at an alternative stalk site, but instead supports the hypothesis that the testis ACE ectodomain contains a motif that activates shedding, which is occluded by the additional domain found in somatic ACE.

Enrichment of specific mRNAs in cytoskeletal-bound and membrane-bound polysomes in Chinese hamster ovary cells

1996 ◽  
Vol 24 (2) ◽  
pp. 187S-187S ◽  
Author(s):  
JOHN HESKETH ◽  
DIEGO JODAR ◽  
ARILD JOHANNESSEN ◽  
KRIS PARTRIDGE ◽  
IAN PRYME ◽  
...  
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Specific Mrnas ◽  
Membrane Bound

scholarly journals Human Acyl-Coenzyme A:Cholesterol Acyltransferase Expressed in Chinese Hamster Ovary Cells: Membrane Topology and Active Site Location

2003 ◽  
Vol 14 (6) ◽  
pp. 2447-2460 ◽  
Author(s):  
Song Lin ◽  
Xiaohui Lu ◽  
Catherine C.Y. Chang ◽  
Ta-Yuan Chang
Keyword(s):  
Chinese Hamster Ovary ◽  
Active Site ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Protein Band ◽  
Membrane Topology ◽  
Site Location ◽  
Ovary Cells ◽  
Membrane Bound ◽  
Cytoplasmic Side

Acyl-CoA:cholesterol acyltransferase (ACAT) is a membrane-bound enzyme that produces cholesteryl esters intracellularly. Two ACAT genes (ACAT1 and ACAT2) have been identified. The expression of ACAT1 is ubiquitous, whereas that of ACAT2 is tissue restricted. Previous research indicates that ACAT1 may contain seven transmembrane domains (TMDs). To study ACAT2 topology, we inserted two different antigenic tags (hemagglutinin, monoclonal antibody Mab1) at various hydrophilic regions flanking each of its predicted TMDs, and expressed the recombinant proteins in mutant Chinese hamster ovary cells lacking endogenous ACAT. Each tagged ACAT2 was expressed in the endoplasmic reticulum as a single undegraded protein band and was at least partially active enzymatically. We then used cytoimmunofluorescence and protease protection assays to monitor the sidedness of the hemagglutinin and Mab1 tags along the ER membranes. The results indicated that ACAT2 contains only two detectable TMDs, located near the N terminal region. We also show that a conserved serine (S245), a candidate active site residue, is not essential for ACAT catalysis. Instead, a conserved histidine (H434) present within a hydrophobic peptide segment, may be essential for ACAT catalysis. H434 may be located at the cytoplasmic side of the membrane.

scholarly journals Characterization of the first non-insect invertebrate functional angiotensin-converting enzyme (ACE): leech TtACE resembles the N-domain of mammalian ACE

2004 ◽  
Vol 382 (2) ◽  
pp. 565-573 ◽  
Author(s):  
Guillaume RIVIÈRE ◽  
Annie MICHAUD ◽  
Laurence DELOFFRE ◽  
Franck VANDENBULCKE ◽  
Angélique LEVOYE ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Active Site ◽  
Active Sites ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Inhibitory Effect ◽  
Converting Enzyme ◽  
Ovary Cells

Angiotensin-converting enzyme (ACE) is a zinc metallopeptidase that plays a major role in blood homoeostasis and reproduction in mammals. In vertebrates, both transmembrane and soluble ACE, containing one or two homologous active sites, have been characterized. So far, several ACEs from invertebrates have been cloned, but only in insects. They are soluble and display a single active site. Using biochemical procedures, an ACE-like activity was detected in our model, the leech, Theromyzon tessulatum. Annelida is the most distant phylum in which an ACE activity has been observed. To gain more insight into the leech enzyme, we have developed a PCR approach to characterize its mRNA. The approx. 2 kb cDNA has been predicted to encode a 616-amino-acid soluble enzyme containing a single active site, named TtACE (T. tessulatum ACE). Surprisingly, its primary sequence shows greater similarity to vertebrates than to invertebrates. Stable in vitro expression of TtACE in transfected Chinese-hamster ovary cells revealed that the leech enzyme is a functional metalloprotease. As in mammals, this 79 kDa glycosylated enzyme functions as a dipeptidyl carboxypeptidase capable of hydrolysing angiotensin I to angiotensin II. However, a weak chloride inhibitory effect and acetylated N-acetyl-SDKP (Ac SDAcKP) hydrolysis reveal that TtACE activity resembles that of the N-domain of mammalian ACE. In situ hybridization shows that its cellular distribution is restricted to epithelial midgut cells. Although the precise roles and endogenous substrates of TtACE remain to be identified, characterization of this ancestral peptidase will help to clarify its physiological roles in non-insect invertebrate species.

Malignancy-related characteristics of wild type and drug-resistant chinese hamster ovary cells

Pathology ◽  
1993 ◽  
Vol 25 (3) ◽  
pp. 268-276 ◽  
Author(s):  
Wanda B. Mackinnon ◽  
Marlen Dyne ◽  
Rebecca Hancock ◽  
Carolyn E. Mountford ◽  
Adrienne J. Grant ◽  
...  
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Drug Resistant ◽  
Wild Type ◽  
Ovary Cells

Review of the current methods of Chinese Hamster Ovary (CHO) cells cultivation for production of therapeutic protein

2020 ◽  
Vol 17 ◽  
Author(s):  
Shazid Md. Sharker ◽  
Md. Atiqur Rahman
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Mass Production ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Therapeutic Protein ◽  
Specific Productivity ◽  
Ovary Cells ◽  
Further Development ◽  
Interesting Area

Most of clinical approved protein-based drugs or under in clinical trial have a profound impact in the treatment of critical diseases. The mammalian eukaryotic cells culture approaches, particularly the CHO (Chinese Hamster Ovary) cells are mainly used in the biopharmaceutical industry for the mass-production of therapeutic protein. Recent advances in CHO cell bioprocessing to yield recombinant proteins and monoclonal antibodies have enabled the expression of quality protein. The developments of cell lines are possible to upgrade specific productivity. As a result, it holds an interesting area for academic as well as industrial researchers around the world. This review will concentrate on the recent progress of the mammalian CHO cells culture technology and the future scope of further development for the mass-production of protein therapeutics.

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