Perhaps you are a fan of Twilight the movie or the Twilight series by Stephenie Meyer, or True Blood the television drama series created and produced by Alan Ball, based on The Southern Vampire Mysteries series of novels by Charlaine Harris. Vampires with their frightening appearance and unusual powers and weaknesses can cause one to pause and question how this is possible. Can this mythicalogical being brought to life in Dracula, the 1897 novel by Irish author Bram Stoker, featuring as its primary antagonist the vampire Count Dracula, have any basis in reality? Is there any connection to what we know about biological systems that could explain vampirism? I doubt that you would be surprised if I said yes, since this is a biochemistry course website.
Although I am no expert on the vampire mythology or the speculative scientific explanations, there are a few possibilities that others have proposed. Perhaps the most robust explanation is that the vampirism is based on the viral disease rabies (Gomez, 1982; 1992; 1998). The vampire folklore originated in Central Europe in the latter half of the 18th century where injuries caused by rabid dogs and wolves was common (Theodorides 1986). At this time, Eastern Europe was rife with claims of vampire sightings. The 3-dimensional structure of the rabies virus nucleoprotein-RNA complex is shown to the right, and what an incredibly amazing structure it has.
Perhaps the most defining characteristic of a vampire is the biting of its human victim. This affirms the fact that a vampire is a living being, and as such he or she becomes inclined to bite those around them and not only to feed on a victim’s blood, but potentially spread the disease that has already infected them (Theodorides 1998). This is strikingly similar to what can occur when rabies has been transmitted to a person. Disease symptoms include cerebral dysfunction, anxiety, insomnia, confusion, agitation, paranoia and a terror progressing to delirium. Large quantities of saliva and tears are produced, and difficulty swallowing stemming from throat and jaw paralysis causes panic when the person cannot drink or quench his or her thirst. Who hasn’t heard of rabid animals indiscriminately attacking and biting someone?
Dr. David H. Dolphin in a lecture at an AAAS meeting is attributed to have proposed an alternative explanation for the vampire myth that werewolves and vampires may have been based on people suffering from a rare class of genetic diseases known as porphyrias. He suggested that characteristics commonly associated with vampirism such as protruding teeth, avoidance of sunlight, drinking blood, and disfigurement could have been the symptoms of people with a porphyria. Porphyrias are a group of rare genetic diseases that primarily manifest their effects in blood as a result of a defect in the production and synthesis of the heme prosthetic group in hemoglobin (Cox 1995). Symptoms of the disorder porphyria cutanea tarda include disfigurement by light-induced blisters that can cause scarring and skin discoloration. In severe cases, excessive hair growth on the face and hands, gum degeneration, and neurological disorders can occur. Those suffering from a porphyria must avoid the sun and some compounds that can exacerbate the symptoms, including certain metabolites that accumulate in, you guessed it, garlic. Repeated blood transfusions can be required to treat the disease.
Porphyria cutanea tarda results from a dominant mutation in the gene encoding the enzyme urophopyrinogen decarboxylase (Taylor 1998). This enzyme catalyzes the fifth step in the porphyrin biosynthetic pathway that produces precursors for the synthesis of heme-containing molecules. Mutant skin cells accumulate uroporphyrinogen, the enzyme’s immediate precursor. Uroporphyrinogen when illuminated by light will become highly reactive and begin transferring electrons to molecular oxygen. The resulting production and accumulation of reactive oxygen species will cause extensive damage to skin cells and can kill them.
Hampl and Hampl (1997) have suggested that a deficiency of niacin and tryptophan could produce symptoms compatible with being the basis for the vampire myth. Pellagra is a vitamin deficiency disease characterized by lack of niacin (vitamin B3) caused by decreased intake of niacin, tryptophan, or possibly leucine. The protein amino acid tryptophan is a precursor of niacin biosynthesis and niacin is a building block of the nicotinamide coenzymes essential for a host of biochemical processes. People suffering from pellagra are hypersensitive to sunlight. The skin of a pellargrin exposed to sunlight becomes red, scaly and marked by hyperkeratosis. Inflammation and edema can occur and lead to depigmented, shiny skin and/or brown scaly areas. Niacin deficiency will also cause brain degeneration and dementia with symptoms that include insomnia, anxiety, unjustified aggression, and depression. Pica can accompany pellagra. Pica is a craving for substances not usually regarded as food such as ice, clay or other crunchy substances. This odd symptom can be a cause of iron deficiency, or a symptom of an iron deficiency in the person who has become anemic. A pellagrin who happens to become extremely anemic because of gastrointestinal bleeding could give the impression of being 'the living dead' (Hampl and Hampl 1997).
So there you have it. There could be a connection between the folklore of vampirism, and clinical symptoms of known diseases, or just as likely perhaps not. We will never know for sure, but this little story briefly illustrates how biochemistry can relate to myths and classical literature and suggest interesting possibilities.
Albertini A.A., Wernimont A.K., Muziol T., Ravelli R.B., Clapier C.R., Schoehn G., Weissenhorn W., Ruigrok R.W. (2006) Crystal structure of the rabies virus nucleoprotein-RNA complex. Science 313, 360-363.
COX A.M. 1995. Porphyria and vampirism: another myth in the making. Postgrad. Med. J. 71: 643–644.
Gomez-Alonso J. 1982.Rabia y vampirismo: hiptjtesis sobre una interpretacion medica del vampirismo. Jano (Barcelona) 514: 30-33.
Gomez-Alonso J. Rabia y Vampirismo en la Europa de los Siglos XVIII y XIX. Tesis Doctoral. Madrid: Facultad de Medicina
Gomez-Alonso, J. 1998. Rabies A possible explanation for the vampire legend. Neurology 51: 856-859
Hampl J.S. and Hampl W.S. 1997. Pellagra and the origin of a myth: evidence from European literature and folklore. J. Royal Soc. Med. 90: 636-639.
Taylor, C.B. 1998. Vampire Plants? Plant Cell. 10: 1071-1073.
Theodorides J. 1986. Histoire de la Rage, Cave Canem, Paris: Masson, 78-9
Theodorides J. 1998. Origin of the myth of vampirism. J. Royal Soc. Med. 91: 114.
Dr. Charles Guy
Dept. of Env. Hort.
University of Florida
BCH 5045 GRADUATE SURVEY OF BIOCHEMISTRY OnLine, FALL 2009