L-lactate dehydrogenase B chain (LDHB)
The protein contains 334 amino acids for an estimated molecular weight of 36638 Da.
No function (updated: April 1, 2015)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
Biological Process
Carbohydrate metabolic process
Cellular carbohydrate metabolic process
Cellular metabolic process
Lactate metabolic process
NAD metabolic process
Pyruvate metabolic process
Small molecule metabolic process
Cellular Component
Cytoplasm
Cytosol
Extracellular exosome
Membrane
Membrane raft
Mitochondrion
Myelin sheath
Molecular Function
Identical protein binding
Kinase binding
L-lactate dehydrogenase activity
NAD binding
The reference OMIM entry for this protein is 150100
Lactate dehydrogenase b; ldhb
Ldh, subunit h
The LDHB gene encodes the B subunit of lactate dehydrogenase (EC 1.1.1.27), an enzyme that catalyzes the interconversion of lactate and pyruvate (summary by Markert, 1984).
CLONING
Sakai et al. (1987) isolated and sequenced LDHB cDNA. The deduced LDHB protein contains 333 amino acids. Nucleotide and amino acid sequences for the LDHB enzyme showed 68% and 75% identity, respectively, with those of LDHA (150000).GENE STRUCTURE
Takeno and Li (1989) determined that the LDHB gene contains 7 coding exons.MAPPING
LDHB and peptidase B (169900) are linked (Santachiara et al., 1970) and both loci are on chromosome 12 (Chen et al., 1973). In a case of deletion of the short arm of chromosome 12, Weiss et al. (1973) found evidence that LDHB is located there. From study of somatic cell hybrids Hamerton et al. (1975) concluded that LDHB is in the 12pter-q21 region. Rethore et al. (1975) found augmentation of LDHB activity in a boy trisomic for the short arm of chromosome 12. From study of 3 patients with different deletions of chromosome 12, Rethore et al. (1976) concluded that the G3PD locus (138400) is on the distal part of 12p and that the LDHB locus is on the middle third between 12p12.1 and 12p12.2. Steinbach and Rehder (1987) demonstrated dosage effect with LDHB in a case of tetrasomy of 12p. - Pseudogenes Sudo et al. (1990) demonstrated 93% homology between an LDHB processed pseudogene and the functional gene. The pseudogene was mapped to the X chromosome by dot-blot analysis.GENE FUNCTION
The LDHB AND LDHA (150000) subunits generate 5 tetrameric isozymes. Although all LDH isozymes catalyze the interconversion of pyruvate and lactate, they do so with different kinetics. The B subunits in heart muscle are bound to NAD. Heart muscle B4 isozymes function principally to oxidize lactic acid to pyruvate with the generation of NADH which, in turn, is oxidized through the cytochrome system to generate energy to support the normal physiology of the heart. Through a negative feedback system involving LDHB, a constant ratio of NAD to NADH is maintained (summary by Markert, 1984).MOLECULAR GENETICS
Mohrenweiser and Neel (1981) identified thermolabile variants of lactate dehydrogenase B, glucosephosphate isomerase, and glucose-6-phosphate dehydrogenase. None was detectable as a variant by standard electrophoretic techniques. All were inherited. In a clinically normal 43-year-old male who was found to have low LDH activity in serum by Houki et al. (1986), Sudo et al. (1990) identified a homozygous mutation in the LDHB gene (150100.0001). LDHB mutations have been found in other individuals with LDHB deficiency (see, e.g., 150100.0002-150100.0004). Okumura et al. (1999) tabulated the LDHB variants caused by missense mutations. ... More on the omim web site
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 150100 was added.
Jan. 28, 2016: Protein entry updated
Automatic update: model status changed
Jan. 24, 2016: Protein entry updated
Automatic update: model status changed