For more than 60 years, scientists have been firing X-rays at crystals of proteins in the quest to determine the three-dimensional make-up of large biological molecules. The results of these endeavours are more than 12 000 often beautiful structures – not just of proteins but DNA, RNA and other molecules. But fewer than 1000 of these structures are of human proteins, and only a few of the new structures produced each year are of human proteins. For tens of thousands of gene sequences – not only from the human genome but also from the genomes of the fruitfly and of microbes – we have no idea of the structure of the protein products and insufficient examples to use computers to model them accurately.
Compared with the manipulation of DNA, almost all aspects of which have been automated, producing just one protein structure can be a laborious and expensive process. Purifying and crystallising the protein can take many months of work, and months more lie ahead as the researcher fires X-rays at the protein crystal and then analyses the results. Structural genomics – in particular producing structures for all the 30–40 000 human proteins – presents a daunting challenge for the structural biology community, as daunting as that facing the DNA sequencers when the Human Genome Project was launched in 1990. Taken from Structural genomics. http://www.wellcome.ac.uk/News/News-archive/Browse-by-date/2001/Features/WTX024053.htm
Yes and no. Salt or sugar crystals are durable and hard, but protein crystals are like fragile cubes of jelly. Growing crystals is something of a black art.
3 Dimensi struktur protein PAPAIN dari pepaya (Carica papaya)
Struktur 3 dimensi protein rapuh seperti juga struktur 3 dimensi jelly dalam cubes/cup