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27 May 2024 | Story Leonie Bolleurs | Photo Supplied
Inaugural
At the inaugural lecture of Prof Dirk Opperman were, from the left: Prof Opperman, Prof Vasu Reddy, Prof Koos Albertyn, Head of the Department of Microbiology and Biochemistry, and Prof Paul Oberholster, Dean of the Faculty of Natural and Agricultural Sciences.

Prof Dirk Opperman, a distinguished biochemist in the Department of Microbiology and Biochemistry, recently (21 May 2024) delivered his inaugural lecture on the Bloemfontein Campus of the University of the Free State (UFS).

The title of his lecture was: Exploring, Exploiting, and Evolving Life at the Atomic Level.

Prof Vasu Reddy, Deputy Vice-Chancellor: Research and Internationalisation at the UFS, welcomed guests, stating, "An inaugural lecture is a major milestone, celebrating a life’s work that culminates in the title of professor. It marks an important chapter in an academic career, with much more to be achieved in the journey of producing important knowledge.”

He believes that an event such as this highlights the university’s pride in the achievements of its academic staff and aligns with Vision 130. “The UFS is proud to host such lectures, as they are significant moments to reveal and showcase the value of excellence in our knowledge pool in research, teaching, and innovation. As a university, we strive to make a difference through groundbreaking work, particularly in addressing society's challenges,” said Prof Reddy, emphasising that this topic truly speaks to the university’s commitment to impactful work in the hard sciences.

Deciphering the unknown

The topic of the lecture captures the essence of Prof Opperman’s research. He explains that ‘exploring’ refers to the determination of the three-dimensional structures of proteins and enzymes. ‘Exploiting’ involves the use of these enzymes to convert substrates into products of value, and ‘evolving’ pertains to mutating the DNA to change the protein, giving it different functions, activities, selectivity, or specificities.

In his lecture, he remarked that if we know the structures of these proteins and enzymes, we can explore what to do with them and how to change them. According to him, there are the unknown knowns, the unknown unknowns, and the known unknowns. “We may know of specific activities and reactions by microorganisms, but we don’t know which enzyme is responsible; similarly, we can know the reactivity of an enzyme, but not necessarily their true physiological functions. I am trying to figure out all these unknowns,” he said.

In his lecture, he also raised the question of whether AI could replace experimental determination of protein structures. "No, not yet; it is only predictions," he believes, commenting that navigating the unknown unknowns is a dangerous place in science.

Establishing the field of structural biology

Prof Opperman, born and raised in the Free State, completed his undergraduate studies at the UFS. Later, in 2008, he obtained his PhD in Biochemistry from the same university. Following his doctoral studies, he conducted postdoctoral research on directed evolution under the guidance of Prof Manfred T Reetz at the Max Planck Institute for Coal Research in Germany, one of the world’s top institutions.

In 2010, he was appointed to the Department of Microbiology and Biochemistry at the UFS, where he has since established the field of structural biology, setting up the infrastructure essential for the advancement thereof. This includes equipment, techniques, and methods for determining the three-dimensional structure of proteins. “It is done using protein crystallisation and then X-ray diffraction,” he explains. Most of these X-ray diffraction experiments are then performed at particle accelerators called synchrotrons, such as Diamond Light Source (UK), which can produce intense X-rays.

His current research explores the interface of evolutionary and structure-function relationships of biocatalysts, with a particular focus on their application in green chemistry. Prof Opperman says that understanding both the structure and the function of an enzyme allows one to manipulate it to perform other functions.

Contributing to the broader goals of sustainable development

One of the projects he is working on highlights the potential for sustainable practices in waste management. Prof Opperman is currently part of a European Research Area Network Cofund partnership on Food Systems and Climate (FOSC), which focuses on developing biocatalysts for upcycling waste. An aspect of this work involves studying enzymes that degrade feathers, thereby converting feather waste into useful products such as fertiliser.

Regarding the contribution of his research to the broader goals of sustainable development and environmental protection, he says that enzymes are the base for biotechnology and the bioeconomy. “They can be sustainably produced, the reactions are environmentally friendly, and the resulting products can be classified as natural. There’s no need to use sources that are not sustainable to extract some of these molecules from,” he explains.

His significant contributions to the field are reflected in more than 50 authored and co-authored papers, some of which are published in prestigious journals such as Science, Nature Communications, and Angewandte Chemie. As an NRF B-rated researcher, his work has received funding from various local and international organisations, including industries such as Sasol and the Global Challenges Research Fund.

News Archive

To tan or not to tan: a burning issue
2009-12-08

 Prof. Werner Sinclair

“Some evidence exists which implies that sunscreens could indeed be responsible for the dramatic rise in the incidence of melanoma over the past three decades, the period during which the use of sunscreens became very popular,” says Prof. Werner Sinclair, Head of the Department of Dermatology at the University of the Free State. His inaugural lecture was on the topic Sunscreens – Curse or Blessing?

Prof. Sinclair says the use of sunscreen preparations is widely advocated as a measure to prevent acute sunburn, chronic sun damage and resultant premature skin aging as well as skin malignancies, including malignant melanoma. There is inconclusive evidence to prove that these preparations do indeed achieve all of these claims. The question is whether these preparations are doing more harm than good?

He says the incidence of skin cancer is rising dramatically and these tumours are induced mostly by the ultra-violet rays.

Of the UV light that reaches the earth 90-95% belongs to the UVA fraction. UVC is normally filtered out by the ozone layer. UVB leads to sunburn while UVA leads to pigmentation (tanning). Because frequent sunburn was often associated with skin cancer, UVB was assumed, naively, to be the culprit, he says.

Exposure to sunlight induces a sense of well-being, increases the libido, reduces appetite and induces the synthesis of large amounts of vitamin D, an essential nutritional factor. The use of sunscreen creams reduces vitamin D levels and low levels of vitamin D have been associated with breast and colon cancer. Prof. Sinclair says the 17% increase in breast cancer from 1981 to 1991 parallels the vigorous use of sunscreens over the same period.

Among the risk factors for the development of tumours are a family history, tendency to freckle, more than three episodes of severe sunburn during childhood, and the use of artificial UV light tanning booths. He says it remains a question whether to tan or not. It was earlier believed that the main carcinogenic rays were UVB and that UVA merely induced a tan. The increase in UVA exposure could have severe consequences.

Prof. Sinclair says the UV light used in artificial tanning booths consists mainly of pure UVA which are highly dangerous rays. It has been estimated that six per cent of all melanoma deaths in the UK can be directly attributed to the use of artificial tanning lights. The use of an artificial tanning booth will double the melanoma risk of a person. “UVA is solely responsible for solar skin aging and it is ironical that tanning addicts, who want to look beautiful, are inflicting accelerated ageing in the process,” he says.

On the use of sunscreens he says it can prevent painful sunburn, but UVA-induced damage continues unnoticed. UVB blockers decrease vitamin D synthesis, which is a particular problem in the elderly. It also prevents the sunburn warning and therefore increases the UVA dosage that an individual receives. It creates a false sense of security which is the biggest problem associated with sunscreens.

Evidence obtained from the state of Queensland in Australia, where the heaviest and longest use of sunscreens occurred, boasted the highest incidence of melanoma in the world. A huge study in Norway has shown a 350% increase in melanoma for men and 440% for women. This paralleled the increase in the use of UVB blocking sunscreens while there was no change in the ozone layer. It did however, occur during that time when tanning became fashionable in Norway and there was an increase especially in artificial tanning.

Prof. Sinclair says: “We believe that sunscreen use does not directly lead to melanoma, but UVA exposure does. The Melanoma Epidemic is a reality. Sunscreen preparations are not the magical answer in the fight against melanoma and the irresponsible use of these preparations can worsen the problem.”

Media Release
Issued by: Mangaliso Radebe
Assistant Director: Media Liaison
Tel: 051 401 2828
Cell: 078 460 3320
E-mail: radebemt.stg@ufs.ac.za
7 December 2009

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