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serotransferrin; transferrin; Siderophilin; beta-1 metal-binding globulin (TF)

Function: - beta-1 transferrin (aliases serotransferrin; siderophilin) is an iron transport sialoglycoprotein that shuttles iron between liver & tissues, especially bone marrow - can bind 2 Fe+3 ions in association with the binding of an anion, usually bicarbonate - serum transferrin may also have a further role in stimulating cell proliferation Structure: - monomer - beta-1 or serum transferrin contains 4 sialic acid groups which undergo partial desialization in CSF secondary to neuraminidase activity, producing beta-2 or tau transferrin, a cathodally migrating form of transferrin seen on high resolution CSF protein electrophoresis [1] - belongs to the transferrin family contains 2 transferrin-like domains Compartment: secreted Expression: - expressed by the liver & secreted in plasma Polymorphism: - different polymorphic variants of transferrin are known Pathology: - identification of beta-2 transferrin in nasal or aural fluid is specific for CSF leakage - transferrin is a negative Acute Phase reactant - low levels occur, along with low levels of albumin, prealbumin, & beta-lipoprotein, in inflammation & malignancy - defects in transferrin are the cause of atransferrinemia Laboratory: - transferrin carbodydrate deficient in CSF - transferrin in serum - transferrin carbodydrate deficient in CSF - transferrin in stool - transferrin in urine - transferrin gene mutation

Related

CD71; transferrin receptor 1; TfR1; TfR; TR; Trfr; T9; p90; sTfR (TFRC) transferrin in serum

Specific

beta 2 transferrin beta-1 transferrin

General

acute phase protein beta globulin carrier protein (transporter) metalloprotein sialoglycoprotein

Properties

SIZE: entity length = 698 aa MW = 77 kD COMPARTMENT: plasma MOTIF: signal sequence {1-19} Transferrin-like 1 {25-347} MOTIF: cysteine residue {C28} MODIFICATION: cysteine residue {C67} cysteine residue {C38} MODIFICATION: cysteine residue {C58} Ser glycosylation site {S51} cysteine residue {C58} MODIFICATION: cysteine residue {C38} cysteine residue {C67} MODIFICATION: cysteine residue {C28} Iron [Fe]-binding site SITE: 82-82 Iron [Fe]-binding site SITE: 114-114 cysteine residue {C137} MODIFICATION: cysteine residue {C213} binding site SITE: 139-139 FOR-BINDING-OF: Carbonate 1 binding site SITE: 143-143 FOR-BINDING-OF: Carbonate 1 binding site SITE: 145-145 FOR-BINDING-OF: Carbonate 1; via amide nitrogen binding site SITE: 146-146 FOR-BINDING-OF: Carbonate 1; via amide nitrogen cysteine residue {C156} MODIFICATION: cysteine residue {C350} cysteine residue {C177} MODIFICATION: cysteine residue {C193} cysteine residue {C180} MODIFICATION: cysteine residue {C196} cysteine residue {C190} MODIFICATION: cysteine residue {C198} cysteine residue {C193} MODIFICATION: cysteine residue {C177} cysteine residue {C196} MODIFICATION: cysteine residue {C180} cysteine residue {C198} MODIFICATION: cysteine residue {C190} Iron [Fe]-binding site SITE: 207-207 cysteine residue {C213} MODIFICATION: cysteine residue {C137} cysteine residue {C246} MODIFICATION: cysteine residue {C260} cysteine residue {C260} MODIFICATION: cysteine residue {C246} Iron [Fe]-binding site SITE: 268-268 cysteine residue {C350} MODIFICATION: cysteine residue {C156} cysteine residue {C358} MODIFICATION: cysteine residue {C615} Transferrin-like 2 {361-683} MOTIF: cysteine residue {C364} MODIFICATION: cysteine residue {C396} cysteine residue {C374} MODIFICATION: cysteine residue {C387} cysteine residue {C387} MODIFICATION: cysteine residue {C374} cysteine residue {C396} MODIFICATION: cysteine residue {C364} Iron [Fe]-binding site SITE: 411-411 cysteine residue {C421} MODIFICATION: cysteine residue {C693} N-glycosylation site {N432} cysteine residue {C437} MODIFICATION: cysteine residue {C656} Iron [Fe]-binding site SITE: 445-445 cysteine residue {C469} MODIFICATION: cysteine residue {C542} binding site SITE: 471-471 FOR-BINDING-OF: Carbonate 2 binding site SITE: 475-475 FOR-BINDING-OF: Carbonate 2 binding site SITE: 477-477 FOR-BINDING-OF: Carbonate 2; via amide nitrogen binding site SITE: 478-478 FOR-BINDING-OF: Carbonate 2; via amide nitrogen cysteine residue {C493} MODIFICATION: cysteine residue {C684} cysteine residue {C503} MODIFICATION: cysteine residue {C517} cysteine residue {C514} MODIFICATION: cysteine residue {C525} cysteine residue {C517} MODIFICATION: cysteine residue {C503} cysteine residue {C525} MODIFICATION: cysteine residue {C514} Iron [Fe]-binding site SITE: 536-536 Tyr phosphorylation site {Y536} cysteine residue {C542} MODIFICATION: cysteine residue {C469} cysteine residue {C582} MODIFICATION: cysteine residue {C596} cysteine residue {C596} MODIFICATION: cysteine residue {C582} Iron [Fe]-binding site SITE: 604-604 cysteine residue {C615} MODIFICATION: cysteine residue {C358} N-glycosylation site {N630} cysteine residue {C634} MODIFICATION: cysteine residue {C639} cysteine residue {C639} MODIFICATION: cysteine residue {C634} cysteine residue {C656} MODIFICATION: cysteine residue {C437} cysteine residue {C684} MODIFICATION: cysteine residue {C493} cysteine residue {C693} MODIFICATION: cysteine residue {C421} MISC-INFO: CONCENTRATION 200-400 MG/DL

Database Correlations

OMIM correlations MORBIDMAP 190000 UniProt P02787 Pfam PF00405 Entrez Gene 7018 Kegg hsa:7018

References

  1. Zaret et al Clin Chem 38:1901 1992
  2. Tietz Textbook of Clinical Chemistry, 2nd ed. Burtis CA & Ashwood ER (eds), WB Saunders Co, Philadelphia PA, 1993, pg 711-713
  3. UniProt :accession P02787
  4. Wikipedia: transferrin http://en.wikipedia.org/wiki/transferrin
  5. SeattleSNPs http://pga.gs.washington.edu/data/tf/