scholarly journals Improved Production of HIV-1 Subtype C Protease from Transgenic E. Coli

2021 ◽  
Vol 15 (1) ◽  
pp. 168-176
Author(s):  
Uraisha Ramlucken ◽  
Krishna Suresh Babu Naidu ◽  
Patrick Govender

Background: Human Immunodeficiency Virus 1 (HIV-1) subtype C is responsible for the majority of infections of patients in Southern Africa. The HIV protease is a primary target for the development of highly efficient anti-retroviral pharmaceuticals because of its pivotal role in the maturation of the virus in the host cell. For target validation of novel HIV protease inhibitors, there is a need for the availability of an abundance of this protease. Objective: This study reports an optimized method to produce HIV-1 protease derived from HIV-1 subtype C. Methods: It involves the use of a transgenic E. coli strain that overexpresses the native form of the enzyme via inclusion bodies. A stringent method for the isolation, purification, and renaturation resulted in the production of highly pure active HIV-1 protease. In order to facilitate an increase in protease yields, an optimized growth strategy was developed. In this regard, a chemically defined medium with lower glucose content and devoid of essential amino acids of the TCA cycle was used as an alternative to the widely used nutrient-rich Luria Bertani (LB) medium. Results: Results indicated an increase in protease yield up to twice the amount, thereby making this medium an attractive alternative for increasing biomass and HIV protease production for future research. Conclusion: An optimized method for HIV-1 protease derived from HIV-1 subtype C production using chemically defined media was established. This was achieved using a known method to isolate and purify the enzyme with the use of a specialized feeding strategy.

2020 ◽  
Vol 11 ◽  
Author(s):  
Magnus L. R. Carlsson ◽  
Amanda Kristiansson ◽  
Jesper Bergwik ◽  
Selvaraju Kanagarajan ◽  
Leif Bülow ◽  
...  

α1-Microglobulin (A1M) is a small glycoprotein that belongs to the lipocalin protein family. A major biological role of A1M is to protect cells and tissues against oxidative damage by clearing free heme and reactive oxygen species. Because of this, the protein has attracted great interest as a potential pharmaceutical candidate for treatment of acute kidney injury and preeclampsia. The aim of this study was to explore the possibility of expressing human A1M in plants through transient gene expression, as an alternative or complement to other expression systems. E. coli, insect and mammalian cell culture have previously been used for recombinant A1M (rA1M) or A1M production, but these systems have various drawbacks, including additional complication and expense in refolding for E. coli, while insect produced rA1M is heavily modified with chromophores and mammalian cell culture has been used only in analytical scale. For that purpose, we have used a viral vector (pJL-TRBO) delivered by Agrobacterium for expression of three modified A1M gene variants in the leaves of N. benthamiana. The results showed that these modified rA1M protein variants, A1M-NB1, A1M-NB2 and A1M-NB3, targeted to the cytosol, ER and extracellular space, respectively, were successfully expressed in the leaves, which was confirmed by SDS-PAGE and Western blot analysis. The cytosol accumulated A1M-NB1 was selected for further analysis, as it appeared to have a higher yield than the other variants, and was purified with a yield of ca. 50 mg/kg leaf. The purified protein had the expected structural and functional properties, displaying heme-binding capacity and capacity of protecting red blood cells against stress-induced cell death. The protein also carried bound chromophores, a characteristic feature of A1M and an indicator of a capacity to bind small molecules. The study showed that expression of the functional protein in N. benthamiana may be an attractive alternative for production of rA1M for pharmaceutical purposes and a basis for future research on A1M structure and function.


2019 ◽  
Vol 476 (2) ◽  
pp. 375-384 ◽  
Author(s):  
Alison Williams ◽  
Adriaan Basson ◽  
Ikechukwu Achilonu ◽  
Heini W. Dirr ◽  
Lynn Morris ◽  
...  

AbstractHIV protease is essential for processing the Gag polyprotein to produce infectious virions and is a major target in antiretroviral therapy. We have identified an unusual HIV-1 subtype C variant that contains insertions of leucine and asparagine (L38↑N↑L) in the hinge region of protease at position 38. This was isolated from a protease inhibitor naïve infant. Isothermal titration calorimetry showed that 10% less of L38↑N↑L protease was in the active conformation as compared with a reference strain. L38↑N↑L protease displayed a ±50% reduction in KM and kcat. The catalytic efficiency (kcat/KM) of L38↑N↑L protease was not significantly different from that of wild type although there was a 42% reduction in specific activity for the variant. An in vitro phenotypic assay showed the L38↑N↑L protease to be susceptible to lopinavir (LPV), atazanavir (ATV) and darunavir in the context of an unrelated Gag. However, in the presence of the related Gag, L38↑N↑L showed reduced susceptibility to darunavir while remaining susceptible to LPV and ATV. Furthermore, a reduction in viral replication capacity (RC) was observed in combination with the related Gag. The reduced susceptibility to darunavir and decrease in RC may be due to PTAPP duplication in the related Gag. The present study shows the importance of considering the Gag region when looking at drug susceptibility of HIV-1 protease variants.


2019 ◽  
Vol 34 (1) ◽  
pp. 1451-1456 ◽  
Author(s):  
Sibusiso Maseko ◽  
Eden Padayachee ◽  
Siyabonga Maphumulo ◽  
Thavendran Govender ◽  
Yasien Sayed ◽  
...  

PLoS ONE ◽  
2010 ◽  
Vol 5 (9) ◽  
pp. e12463 ◽  
Author(s):  
Morgane Rolland ◽  
Jonathan M. Carlson ◽  
Siriphan Manocheewa ◽  
J. Victor Swain ◽  
Erinn Lanxon-Cookson ◽  
...  

2019 ◽  
Vol 10 (3) ◽  
pp. 686-707
Author(s):  
Marcus Conlé

Purpose The paper aims to take stock of China’s recent biopharmaceutical industry development by analyzing product innovation and changes in the firms’ product portfolios during the five-year period between 2012 and 2017. Design/methodology/approach The paper introduces a classification of biopharmaceutical products. By applying the classification to the product data of China’s drug regulator, the CFDA, it becomes possible to trace the developments within the sector by looking at changes in the number of firms within each subgroup and changes in the number of subgroups in which each firm is involved. The classification allows an evaluation of the latest product innovation achievements. Findings The paper demonstrates a mild shakeout of firms in the relatively long-existing domestic market segments, a trend toward more specialized product portfolios and an enduring prevalence of innovation strategies aimed at exploiting relatively unpopulated domestic market niches instead of pioneering entirely new products. Especially the capability of upgrading to second-generation protein therapeutics has become a key criterion for separating the wheat and the chaff in China’s domestic sector. The paper moreover points out the relevance of acquisitions as a corporate growth strategy. Research limitations/implications The research does not consider complementary indicators, product pipelines in particular. Future research should compare patterns across emerging economies. Originality/value The paper is unique in using the CFDA database for systematic academic research on (bio)pharmaceutical innovation and in introducing a biopharmaceutical product classification to trace innovative activities and changes in corporate product portfolios over time.


2021 ◽  
Vol 22 (10) ◽  
pp. 5304
Author(s):  
Ana Santos-Pereira ◽  
Vera Triunfante ◽  
Pedro M. M. Araújo ◽  
Joana Martins ◽  
Helena Soares ◽  
...  

The success of antiretroviral treatment (ART) is threatened by the emergence of drug resistance mutations (DRM). Since Brazil presents the largest number of people living with HIV (PLWH) in South America we aimed at understanding the dynamics of DRM in this country. We analyzed a total of 20,226 HIV-1 sequences collected from PLWH undergoing ART between 2008–2017. Results show a mild decline of DRM over the years but an increase of the K65R reverse transcriptase mutation from 2.23% to 12.11%. This increase gradually occurred following alterations in the ART regimens replacing zidovudine (AZT) with tenofovir (TDF). PLWH harboring the K65R had significantly higher viral loads than those without this mutation (p < 0.001). Among the two most prevalent HIV-1 subtypes (B and C) there was a significant (p < 0.001) association of K65R with subtype C (11.26%) when compared with subtype B (9.27%). Nonetheless, evidence for K65R transmission in Brazil was found both for C and B subtypes. Additionally, artificial neural network-based immunoinformatic predictions suggest that K65R could enhance viral recognition by HLA-B27 that has relatively low prevalence in the Brazilian population. Overall, the results suggest that tenofovir-based regimens need to be carefully monitored particularly in settings with subtype C and specific HLA profiles.


2009 ◽  
Vol 200 (8) ◽  
pp. 1202-1206 ◽  
Author(s):  
Cédric F. Invernizzi ◽  
Dimitrios Coutsinos ◽  
Maureen Oliveira ◽  
Daniela Moisi ◽  
Bluma G. Brenner ◽  
...  

Retrovirology ◽  
2009 ◽  
Vol 6 (S2) ◽  
Author(s):  
Mahesh Bachu ◽  
Rajesh V Murali ◽  
Anil MHKH Babu ◽  
Venkat SRK Yedavalli ◽  
Kuan-Teh Jeang ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document