On Cabbage and Selenium Binding Protein 1

Mutations in the gene encoding Selenium Binding Protein (SELENBP1) on chromosome 1q21 were found in multiple individuals with extra-oral halitosis. These individuals had increased levels of methanethiol and dimethylsulfide in their breath perceived as unpleasantly cabbage-smelling. It was reported to worsen after drinking beer. 

The mutations responsible include rs1553204817 (OMIM: 604188.0001: c.1039G>T); rs758495626 (c.673G>T (p.Gly225Trp)), rs1357490520 (c.481+1G>A disrupting splice site), and rs1553204840 (c.985C>T)

SELENBP1 was identified as a methanethiol oxidase (MTO), catalyzing the conversion of methanethiol (H3C-SH) to hydrogen sulfide (H2S), hydrogen peroxide (H2O2) and formaldehyde (HCHO). If this enzyme is not properly functional, the body will be releasing more Methanethiol  - a volatile and toxic gas with the characteristic smell of rotten cabbage. We get this compound from food - not only the cancer-fighting cabbage family, including radishes, but also orange juice, pineapple, strawberries, asparagus, wheat bread, gruyere cheese, coffee, roasted filberts and even cooked rice. Water, cherries, apples, whole milk, spinach and citrusy fruits could counteract the odor in some individuals. 

Selenium binding protein1 (SELENBP1) has been also associated with a rare disease hypermethioninemia (sometimes accompanied by learning disabilities and neurological problems), several cancers and schizophrenia (downregulated at its onset and upregulated at later stages); hypertension and ischemic heart conditions. Dysregulation of SELENBP1 is common to Zika virus (ZIKV) and dengue infections, and Guillain-Barré syndrome. It was also found to COVID-19.

REFERENCES

Pol A, Renkema GH, Tangerman A, Winkel EG, Engelke UF, De Brouwer AP, Lloyd KC, Araiza RS, Van Den Heuvel L, Omran H, Olbrich H. Mutations in SELENBP1, encoding a novel human methanethiol oxidase, cause extraoral halitosis. Nature genetics. 2018 Jan;50(1):120-9.

Philipp TM, Will A, Richter H, Winterhalter PR, Pohnert G, Steinbrenner H, Klotz LO. A coupled enzyme assay for detection of selenium-binding protein 1 (SELENBP1) methanethiol oxidase (MTO) activity in mature enterocytes. Redox Biology. 2021 Jul 1;43:101972.

Lin X, Lin Z, Zhao X, Liu Z, Xu C, Yu B, Gao P, Wang Z, Ge J, Shen Y, Li L. Serum SELENBP1 and VCL Are Effective Biomarkers for Clinical and Forensic Diagnosis of Coronary Artery Spasm. International Journal of Molecular Sciences. 2022 Oct 31;23(21):13266.

Chau EJ, Mostaid MS, Cropley V, McGorry P, Pantelis C, Bousman CA, Everall IP. Downregulation of plasma SELENBP1 protein in patients with recent-onset schizophrenia. Progress in Neuro-Psychopharmacology and Biological Psychiatry. 2018 Jul 13;85:1-6.

Zhang X, Hong R, Bei L, Hu Z, Yang X, Song T, Chen L, Meng H, Niu G, Ke C. SELENBP1 inhibits progression of colorectal cancer by suppressing epithelial–mesenchymal transition. Open Medicine. 2022 Jan 1;17(1):1390-404.

Moni MA, Lio’ P. Genetic profiling and comorbidities of zika infection. The Journal of infectious diseases. 2017 Sep 15;216(6):703-12.

de Melo CV, Bhuiyan MA, Gatua WN, Kanyerezi S, Uzairue L, Abechi P, Kumar K, Rahmat J, Giwa A, Mwandira G, Olamilekan AM. Transcriptomic dysregulations associated with SARS-CoV-2 infection in human nasopharyngeal and peripheral blood mononuclear cells. bioRxiv. 2020 Jan 1.

Albert-Puleo M. Physiological effects of cabbage with reference to its potential as a dietary cancer-inhibitor and its use in ancient medicine. Journal of ethnopharmacology. 1983 Dec 1;9(2-3):261-72.

Odor-prints: individual but genetic connections unclear

Odor is like fingerprints or facial features - it's unique.  Yet no single measurement could be easily applied to recognize an individual.

GC/MS measurements can be used to analyze mixtures of acids, alcohols, aldehydes, hydrocarbons, esters, ketones, and nitrogenous molecules in human odor. Complex algorithms mining patterns help to pinpoint the signatures. But could these signatures be easily derived from genetic makeups?

Recent article published in the Journal of Chemical Ecology looked at the usual suspects -  major histocompatibility locus (MHC) and found that these genes do not determine major patterns. 


Volatile carboxylic acids are the most diverse class of known axillary odorants, and the pattern of these acids is genetically determined. These acids  - like vast majority of human odorous compounds - are produced by human microbiome, in this case by skin bacteria. Odors of 12 families, comprising 3 to 6 siblings,were analyzed with comprehensive two-dimensional gas chromatography (GC x GC) and time-of-flight mass spectrometry (ToF MS). the analysis onfirmed the presence of individual signatures. but failed to find odors specific to HLA genes.

Even though paternally inherited HLA-associated odors were proposed to influence women odor preferences, genetic basis of odors may be more complicated than previously thought.

References

Natsch A, Kuhn F, & Tiercy JM (2010). Lack of Evidence for HLA-Linked Patterns of Odorous Carboxylic Acids Released from Glutamine Conjugates Secreted in the Human Axilla. Journal of chemical ecology PMID: 20623248

Thompson EE, Haller G, Pinto JM, Sun Y, Zelano B, Jacob S, McClintock MK, Nicolae DL, Ober C. (2010) Sequence variations at the human leukocyte antigen-linked olfactory receptor cluster do not influence female preferences for male odors. Hum Immunol. 2010 Jan;71(1):100-3. PMID: 19833159 
 
Jacob S, McClintock MK, Zelano B, Ober C (2002) Paternally inherited HLA alleles are associated with women's choice of male odor. Nature Genet 30: 175-179  PMID: 11799397  PDF