My Journey to becoming a START Postdoc Research Fellow – Dr Andani Mulelu’s story

As a young structural biology research scientist, Dr Andani Mulelu has already achieved what many dream of happening in a lifetime.  His journey to becoming a GCRF START Postdoctoral Research Fellow at the University of Cape Town (UCT) is one to inspire a new generation of African scientists, showing how UK and Africa can work together to support talented individuals and excellent research with impact. Here is Dr Mulelu’s story in his own words.

Dr Andani Mulelu at the University of Cape Town.
Photo Credit: Rebekka Stredwick. ©Diamond Light Source

Dr Andani’s Mulelu’s story

I was born in the Limpopo region of South Africa to parents who had a rural upbringing under apartheid. One of four children, I soon benefited from a multitude of sacrifices made by my parents to send me to school to get a good education. My parents borrowed heavily to educate us, going without even the basics sometimes so that we might gain from every cent they made.

By the time I went to school, Apartheid had fallen, and I was sent to Zimbabwe to get an education at a boarding high school. Zimbabwe’s education was second to none in Africa and my father, who wasn’t able to pursue a civil engineering career under Apartheid restrictions, gave me the opportunities he and my mother never had.

I had a strong interest in science from an early age – at some point in high school one of my Biology teachers told us about biochemistry and I was instantly hooked! I had great teachers who motivated me and due to changing schools and countries a number of times (South Africa, Botswana and Zimbabwe), I learnt to study by myself to adapt to different curricula which set a pattern that has benefitted me to this day.  Yet school in a country rocked by economic hardship was not plain sailing. By the time my O-Levels were almost complete, I had to queue for hours to buy food because of shortages at school.

After my A-Levels, my parents had to fund my undergraduate studies at the University of Cape Town, while funding school for my siblings. A creative woman, my mother was not shy of trying new income sources and started a small business selling ‘mopane worms’, a nutritious caterpillar considered a delicacy in Southern Africa. Soon she was earning the same as my father, an engineer!

In terms of my studies, during my honours year I became fascinated by the structure of helical nitrilases, especially those that detoxified cyanide which has all sorts of potential such as cleaning up pollution from mining, and other worthy applications. Nitrilases are helical enzymes that convert nitriles to acids and/or amides (amides are organic compounds containing nitrogen).

I joined Professor Trevor Sewell’s group at UCT for my Master’s degree and my PhD and worked with an international team of scientists located in the United States, UK and Germany. This provided access to ever-improving electron microscopes to visualise our nitrilases at higher and higher resolutions.

Dr Andani Mulelu with scientists (from left to right) Priscillia Masamba,
Dr Jeremy Woodward, Melissa Marx, Philip Venter, Dr Lizelle Lubbe and
Professor Trevor Sewell at the University of Cape Town.
Photo Credit: Rebekka Stredwick. ©Diamond Light Source

The next big milestones took place after my PhD.  I was appointed a START Postdoctoral Research Fellow in the prestigious Global Challenges Research Funded programme at the University of Cape Town’s Division of Medical Biochemistry and Structural Biology (Faculty of Health Sciences). Then, working with Dr Jeremy Woodward and Angela M. Kirykowicz, we were able to visualise the structure of an intact helical filament at close-to-atomic resolution for the first time – the first high resolution visualisation of a Cryo-EM protein structure ever to be produced in Africa!

Dr Mulelu and Dr Woodward next to UCT’s cryo-electron microscope.
Photo Credit: Rebekka Stredwick. ©Diamond Light Source

The findings were published on the 17 July 2019 in Nature Communications Biology 2:260 (2019) and enabled me to finally realise my dream of visualising a nitrilase at atomic resolution and to solve the mystery of substrate selectivity in these enzymes. These results were made possible through our collaboration through GCRF START, access to the state-of-the-art eBIC facilities and expertise at the UK’s world-class synchrotron light source, Diamond.

In years to come, we hope these findings can be used to address some of the main challenges for humanity in terms of health and the environment – solutions which could contribute to meeting the key UN’s Sustainable Development goals through new ways of designing and manufacturing medicines and ‘green’ biotechnology solutions for agriculture and waste treatment here in Africa.

In addition to our successful results, I landed a job as a Research Scientist at H3D Drug Discovery and Development Centre at UCT! H3D is the first integrated drug discovery and development centre on the African continent and I am responsible for providing scientific and technical support in protein expression and purification, structural biology and running biochemical assays to increase the capacity of H3D’s Malaria and Tuberculosis (TB) target based drug discovery programs.

I can truly say that the START program has given me invaluable training and experience in structural biology, particularly in Cryo-Electron microscopy.  Although I am no longer a research scientist with START, working at H3D also brings new opportunities of continued collaboration with START.

On a personal level, the impact on my family and my future ambitions is huge. My parents are very proud of my achievements, and I thank them from my heart for their support. One of my siblings is also pursuing a PhD, and another is similarly inspired to help solve health challenges working for an NGO specialising in water supply and sanitation for disadvantaged schools.

Finally, I am financially independent! I can happily give back to support my deserving parents, and I am much closer to my long-held dream of being a world-class scientist!

Dr Mulelu visiting the UK’s Diamond Light Source synchrotron.
Photo Credit: Dr Mulelu

Related articles:

https://www.news.uct.ac.za/article/-2020-02-28-biochemistry-breakthrough-for-uct-researchers https://www.diamond.ac.uk/Science/Research/Highlights/2019/Designer-enzymes-on-the-way.htm

Double first! First synchrotron user from the University of Zululand solves partial structure of the Schistosomiasis (Bilharzia) G4LZI3 universal stress protein

In a ‘double first’, Dr Priscilla Masamba, has become the first University of Zululand student to use the UK’s National Synchrotron Light Source, Diamond, and solve the partial structure of a protein from Schistosoma mansoni. With access to the synchrotron made possible by GCRF START, Priscilla employed sophisticated robotic instruments and macromolecular X-ray crystallography techniques remotely from South Africa to solve the partial structure of the G4LZI3 universal stress protein – a protein regarded as a target for novel medicines for treating the disease Schistosomiasis. The experiments took place in February 2020, using the Diamond’s I04-1 beamline.

Dr Priscilla Masamba in the laboratory at the University of Cape Town.
Photo credit Rebekka Stredwick. ©Diamond Light Source

Schistosomiasis is an acute and chronic disease caused by parasitic worms (schistosomes) endemic in more than 78 countries with an estimated 4 million people infected in South Africa alone. The disease requires an intermediate host, the freshwater snail Bulinus africanus, and occurs most often in rural areas where people become infected during routine agricultural, domestic, occupational, and recreational activities which expose them to infested water.

Only one drug, Praziquantel, is available to treat Schistosomiasis leaving people vulnerable to schistosome resistance and this treatment is only partially effective in treating adults.  The aim of Priscilla ’s research is therefore to generate insights for the design of alternative treatment regimen targeting specific stages during the developmental cycle of the schistosome.

Describing the experiments at Diamond as “close to a cool sci-fi movie,” Dr Masamba was able to control the sophisticated instruments on I04-1 beamline and collect data in real time from the University of Cape Town’s (UCT’s) Aaron Klug Centre for Imaging and Analysis – established as a GCRF START Centre of Excellence for structural biology research.

“Remote data collection at Diamond was so exciting!” Dr Masamba explains, “I could literally control and see a robot that was thousands of miles away on the other side of the world, mount a microscopic crystal (sample) within the firing line of a powerful X-ray beam, and determine the amount of energies released by light emitted from the sample caused by incident X-ray beams, and all of this while working from the laboratory in Cape Town. I didn’t need to get in a plane to achieve the one of the most imperative steps in the crystallography process! The whole experience provided me with rare exposure to the world of X-ray crystallography, impacting my view of science in a spectacular way.”

Proteins are thermodynamically and kinetically responsible for all biochemical processes that occur, and are therefore responsible for coordinating, regulating and dictating numerous metabolic functions. Exposure of the Schistosome parasite to extreme conditions during its developmental stage triggers the expression of heat shock proteins and universal stress proteins, of which the G4LZI3 USP has been identified as a potential druggable target for the development of alternative treatments (schistosomicides). Techniques like X-ray crystallography can provide insight, not only into the composition of these biomolecules, but also into their various interactions with other compounds and their roles in biological mechanisms, an imperative foundation for rational drug design and development.

Before the experiments took place, diffraction of the crystals was first checked at UCT using a diffractometer. Crystals from these conditions were then flash-frozen in liquid nitrogen and shipped to the Diamond synchrotron to be used as samples.

The BART robot and sample holder on beamline I04-1. The drum (Dewar) contains liquid nitrogen, and space for 37 pucks, each containing 16 pins, so 592 samples. These pins and pucks are shipped in a Dewar from South Africa. The robotic arm is grey and is shown ready to pick up the next sample. When it selects the next sample, this is placed onto the goniometer, which holds the sample and rotates it for data collection.
©Diamond Light Source.
The goniometer on beamline I04-1 holds the microscopic crystal on a pin with the sample on the end of it which rotates in the firing line of the powerful X-ray beam.
©Diamond Light Source.

The solved structure of the S. mansoni G4LZI3 is a success story for the University of Zululand, a small resource-constrained university in the rural part of KwaZulu-Natal Province of South Africa. The University of Zululand lacked the resources required for Dr Masamba to achieve all her objectives for her PhD, which meant the collaboration through START in order to carry out the experiments needed was imperative both professionally and personally.

Priscilla is thankful for the guidance and mentoring from her PhD supervisor, Professor Abidemi Paul Kappo, who heads up the Biotechnology and Structural Biology (BSB) Research Group in the Department of Biochemistry and Microbiology at the University of Zululand, and from START Principal Investigator, Professor Trevor Sewell, of UCT’s Aaron Klug Centre for Imaging and Analysis, both of whom helped Priscilla overcome various challenges.

“I have been able to learn and cultivate scarce, critical and sought-after skills here in Africa in the fields of bioinformatics and drug discovery, molecular biology and especially, structural biology,” says Dr Masamba. “These include gene cloning, recombinant protein expression and purification, as well as characterisation of proteins. This has not been an easy task because I am from an underrepresented group in science as a black female and study at a historically-disadvantaged and resource-constrained institution.”

Professor Abidemi Paul Kappo, (left) head of the Biotechnology and Structural Biology (BSB) Research Group in the Department of Biochemistry and Microbiology at the University of Zululand, and START Principal Investigator, Professor Trevor Sewell (right), from the University of Cape Town’s Aaron Klug Centre for Imaging and Analysis.
©Diamond Light Source.

An important objective of the START programme is to increase the number of structural biologists in similar less developed universities in South Africa and across the continent. This can present complex challenges, not least because many students are ill-equipped for work in the field of structural biology.

“A key concept behind the creation of the START Centre of Excellence at UCT’s Aaron Klug Centre for Imaging and Analysis, for example, is to provide the necessary infrastructure to enable senior students and staff at South Africa’s historically disadvantaged universities to access both the human and material resources necessary to overcome the difficulties and determine protein structures,” Professor Sewell says. “We count the collaboration with Professor Paul Abidemi Kappo and Dr Masamba as a major success in this respect.”

This collaboration between Prof. Kappo and Prof. Sewell was enabled by GCRF START with Prof. Sewell providing the technological resource for the G4LZI3 structural biology project, as well as the linkage to Diamond.

“Above all, Professor Sewell’s enthusiasm to train and develop a “critical mass” of students in Structural Biology is second to none,” Prof. Kappo says. “This has been a joint effort and a model of national and international collaboration. In addition to the technological resources through UCT and linkage with Diamond in the UK, funding for this project was provided by the National Research Foundation (NRF) of South Africa through a doctoral bursary awarded Dr Masamba. It is expected that structure-guided drug discovery for schistosomiasis will be the concluding part the project.”

Dr Masamba and Prof. Trevor Sewell with colleagues collaborating with GCRF START at the Aaron Klug Centre for Imaging and Analysis at the University of Cape Town. In the picture from left to right: Dr Priscilla Masamba, Dr Jeremy Woodward, Melissa Marx, Dr Mulelu, Dr Philip Venter, Dr Lizelle Lubbe, Professor Trevor Sewell
Photo Credit: Rebekka Stredwick. ©Diamond Light Source.

About Dr Priscilla Masamba

Born to Congolese parents in the DR Congo, Dr Masamba lived in the UK and Zimbabwe as a child, before moving to South Africa where she matriculated and studied for her first degree in Biological Sciences at Walter Sisulu University, Mthatha. Thereafter, Priscilla joined the Biotechnology and Structural Biology (BSB) Research Group in the Department of Biochemistry and Microbiology at the University of Zululand headed by Prof Abidemi Paul Kappo and registered under his tutelage for a BSc (Hons) degree, followed by an MSc and later a PhD in Biochemistry. Priscilla’s desire is to continue in the path of macromolecular X-ray crystallography of proteins through the NRF Postdoctoral Fellowship in Structural Biology at the University of Johannesburg.

Acknowledgements

Dr Priscilla Masamba extends a special thanks to Dr Brandon Weber (UCT), Dr Phillip Venter (UCT), Kaylene Baron (UCT), and Ndibonani Qokoyi (University of Zululand) who were involved in different ways in the production, purification and crystallisation of the G4LZI3 protein, as well as in data collection.

Structural biology – Improvements in health

The need for health improvement on the African continent continues to be a pressing issue, and START’s emphasis will be on diseases such as HIV-AIDS, malaria, tuberculosis, and African horse sickness that are devastating to human and animal populations. The structural biology strand of START research will support scientists in finding and developing cures by researching and understanding the fundamental molecular structure of certain diseases. Prof. Trevor Sewell from the University of Cape Town explains:

“START will allow us to understand drug targets and cure African diseases. We will establish a collaborating network of seven South African institutions (the Universities of Pretoria, Witwatersrand, North West, Free State, Stellenbosch, Cape Town and the National Institute for Communicable Diseases) that will enable young researchers to boost medical and veterinary research”.

Prof. Trevor Sewell, University of Cape Town

A START project at University of Cape Town led by co-investigator Prof Edward D Sturrock

ACE in complex with the clinically used antihypertensive drug, lisinopril (black sticks; PDB ID: 1O86)

Structural biology of angiotensin converting enzyme and related metalloproteases

Enzymes play important roles in a variety of biological processes in the human body. Angiotensin converting enzyme (ACE) for example, is a metalloprotease which regulates blood pressure and is also involved in scar tissue development (fibrosis). Conditions such as diabetes and tuberculosis can lead to excessive scar tissue formation, which ultimately stops proper organ function. Currently, there is no specific treatment for fibrosis and affected individuals have an average survival period of 2-4 years. Hypertension, on the other hand, is a major risk factor for cardiovascular disease and stroke, which accounted for 15.2 million global deaths in 2016. Our research group, led by Prof Edward Sturrock, is based in the Department of Integrative Biomedical Sciences at the University of Cape Town and has a long-standing interest in ACE and related zinc metalloproteases.

Although ACE inhibitors reduce fibrosis and are widely used for treating hypertension, certain patients experience the life-threatening side-effect of severe swelling below the skin surface of the throat and tongue. With the resources provided by START, we aim to design compounds devoid of this side-effect. Detailed structures of ACE will be solved using X-ray crystallography and cryo-electron microscopy to improve our understanding of how ACE functions and enable the design of antifibrotic and antihypertensive drugs.

START Collaborators – research projects

For information on projects please click on the names below

Stellenbosch University: Professor Erick Strauss and Anton Hamann, post-doc 

Cape Town University, Lauren Arendse