Reviewed, UniProtKB/Swiss-Prot P02749 (APOH_HUMAN)

Names and origin

Protein names

Recommended name:
    Beta-2-glycoprotein 1
Alternative name(s):
    Beta-2-glycoprotein I
      Short name=Beta(2)GPI
      Short name=B2GPI
    Apolipoprotein H
      Short name=Apo-H
    Activated protein C-binding protein
    APC inhibitor
    Anticardiolipin cofactor

Gene names

Name:	APOH
Synonyms:	B2G1

Organism

Homo sapiens (Human)

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo

Protein attributes

Sequence length	345 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Binds to various kinds of negatively charged substances such as heparin, phospholipids, and dextran sulfate. May prevent activation of the intrinsic blood coagulation cascade by binding to phospholipids on the surface of damaged cells.
Subcellular location	Secreted.
Tissue specificity	Expressed by the liver and secreted in plasma.
Miscellaneous	In addition to the conflicts shown in the feature table, Ref.9 reports an N-glycosylation site at Asn-188.
Sequence similarities	Contains 4 Sushi (CCP/SCR) domains.

Ontologies

Keywords
Cellular component	Secreted
Coding sequence diversity	Polymorphism
Domain	Repeat Signal Sushi
Ligand	Heparin-binding
PTM	Glycoprotein
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Biological process	blood coagulation, intrinsic pathway Inferred from direct assay. Source: UniProtKB negative regulation of angiogenesis Inferred from direct assay. Source: UniProtKB negative regulation of endothelial cell migration Inferred from direct assay. Source: UniProtKB negative regulation of endothelial cell proliferation Inferred from direct assay. Source: UniProtKB negative regulation of fibrinolysis Inferred from direct assay. Source: UniProtKB negative regulation of myeloid cell apoptosis Inferred from direct assay. Source: UniProtKB negative regulation of smooth muscle cell apoptosis Inferred from direct assay. Source: UniProtKB plasminogen activation Inferred from direct assay. Source: UniProtKB positive regulation of blood coagulation Traceable author statement. Source: UniProtKB positive regulation of lipoprotein lipase activity Inferred from direct assay. Source: UniProtKB triacylglycerol metabolic process Inferred from direct assay. Source: UniProtKB triacylglycerol transport Inferred from sequence or structural similarity. Source: UniProtKB
Cellular component	cell surface Inferred from direct assay. Source: UniProtKB chylomicron Inferred from direct assay. Source: UniProtKB cytoplasm Inferred from direct assay. Source: HPA high-density lipoprotein particle Inferred from direct assay. Source: UniProtKB nucleus Inferred from direct assay. Source: HPA very-low-density lipoprotein particle Inferred from direct assay. Source: UniProtKB
Molecular function	eukaryotic cell surface binding Inferred from direct assay. Source: UniProtKB glycoprotein binding Inferred from physical interaction. Source: UniProtKB heparin binding Inferred from electronic annotation. Source: UniProtKB-KW lipoprotein lipase activator activity Inferred from direct assay. Source: UniProtKB phospholipid binding Inferred from direct assay. Source: UniProtKB
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Signal peptide

1 – 19

19

Chain

20 – 345

326

Beta-2-glycoprotein 1

PRO_0000002059

Regions

Domain

21 – 81

61

Sushi 1

Domain

82 – 139

58

Sushi 2

Domain

140 – 202

63

Sushi 3

Domain

203 – 262

60

Sushi 4

Region

263 – 345

83

Sushi-like

Amino acid modifications

Glycosylation

149

1

O-linked (GalNAc...)

Glycosylation

162

1

N-linked (GlcNAc...)

Glycosylation

183

1

N-linked (GlcNAc...)

Glycosylation

193

1

N-linked (GlcNAc...)

Glycosylation

253

1

N-linked (GlcNAc...)

Disulfide bond

23 ↔ 66

Disulfide bond

51 ↔ 79

Disulfide bond

84 ↔ 124

Disulfide bond

110 ↔ 137

Disulfide bond

142 ↔ 188

Disulfide bond

174 ↔ 200

Disulfide bond

205 ↔ 248

Disulfide bond

234 ↔ 260

Disulfide bond

264 ↔ 315

Disulfide bond

300 ↔ 325

Disulfide bond

307 ↔ 345

Natural variations

Natural variant

107

1

S → N in allele APOH*1. dbSNP rs1801692.

VAR_008169

Natural variant

154

1

R → H

VAR_019155

Natural variant

266

1

V → L in 23% of the population. dbSNP rs4581.

VAR_000673

Natural variant

325

1

C → G Loss of phosphatidylserine-binding. dbSNP rs1801689.

VAR_008170

Natural variant

335

1

W → S in allele APOH*3W; loss of phosphatidylserine-binding. dbSNP rs1801690.

VAR_008171

Experimental info

Sequence conflict

121

1

S → C AA sequence Ref.9

Sequence conflict

188

1

C → N AA sequence Ref.9

Secondary structure

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345

Helix Strand Turn

Details...

Beta strand

23 – 25

3

Beta strand

32 – 36

5

Beta strand

39 – 41

3

Beta strand

46 – 51

6

Beta strand

55 – 60

6

Beta strand

63 – 65

3

Beta strand

79 – 81

3

Beta strand

93 – 96

4

Beta strand

105 – 110

6

Beta strand

114 – 118

5

Beta strand

120 – 124

5

Beta strand

128 – 132

5

Beta strand

136 – 139

4

Beta strand

151 – 155

5

Beta strand

163 – 165

3

Beta strand

169 – 174

6

Beta strand

178 – 182

5

Beta strand

184 – 188

5

Beta strand

192 – 194

3

Beta strand

199 – 202

4

Beta strand

214 – 217

4

Beta strand

229 – 234

6

Beta strand

238 – 242

5

Beta strand

244 – 248

5

Beta strand

252 – 255

4

Beta strand

260 – 262

3

Beta strand

267 – 270

4

Beta strand

272 – 275

4

Beta strand

278 – 281

4

Helix

282 – 285

4

Turn

286 – 288

3

Beta strand

295 – 301

7

Turn

303 – 305

3

Beta strand

308 – 314

7

Turn

331 – 333

3

Helix

339 – 341

3

Sequences

	Sequence		Length	Mass (Da)
	P02749-1 [UniParc]. Last modified June 1, 1994. Version 3. Checksum: 63101704F8EDFE3F	FASTA	345	38,298
	10 20 30 40 50 60 MISPVLILFS SFLCHVAIAG RTCPKPDDLP FSTVVPLKTF YEPGEEITYS CKPGYVSRGG 70 80 90 100 110 120 MRKFICPLTG LWPINTLKCT PRVCPFAGIL ENGAVRYTTF EYPNTISFSC NTGFYLNGAD 130 140 150 160 170 180 SAKCTEEGKW SPELPVCAPI ICPPPSIPTF ATLRVYKPSA GNNSLYRDTA VFECLPQHAM 190 200 210 220 230 240 FGNDTITCTT HGNWTKLPEC REVKCPFPSR PDNGFVNYPA KPTLYYKDKA TFGCHDGYSL 250 260 270 280 290 300 DGPEEIECTK LGNWSAMPSC KASCKVPVKK ATVVYQGERV KIQEKFKNGM LHGDKVSFFC 310 320 330 340 KNKEKKCSYT EDAQCIDGTI EVPKCFKEHS SLAFWKTDAS DVKPC

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Complete nucleotide and deduced amino acid sequence of human beta 2-glycoprotein I." Steinkasserer A., Estaller C., Weiss E., Sim R.B., Day A.J. Biochem. J. 277:387-391(1991) [PubMed: 1650181] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Liver.
[2]	"Molecular cloning and mammalian expression of human beta 2-glycoprotein I cDNA." Kristensen T., Schousboe I., Boel E., Mulvihill E.M., Hansen R.R., Moeller K.B., Moeller N.P.H., Sottrup-Jensen L. FEBS Lett. 289:183-186(1991) [PubMed: 1655523] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Liver.
[3]	"Nucleotide sequence and expression of the human gene encoding apolipoprotein H (beta 2-glycoprotein I)." Mehdi H., Nunn M., Steel D.M., Whitehead A.S., Perez M., Walker L., Peeples M.E. Gene 108:293-298(1991) [PubMed: 1748314] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Liver.
[4]	"Molecular cloning and sequence analysis of the cDNA encoding human apolipoprotein H (beta 2-glycoprotein I)." Day J.R., O'Hara P.J., Grant F.J., Lofton-Day C.E., Berkaw M.N., Werner P., Arnaud P. Int. J. Clin. Lab. Res. 21:256-263(1992) [PubMed: 1339416] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[5]	"Molecular definition of human beta 2-glycoprotein I (beta 2-GPI) by cDNA cloning and inter-species differences of beta 2-GPI in alternation of anticardiolipin binding." Matsuura E., Igarashi M., Igarashi Y., Nagae H., Ichikawa K., Yasuda T., Koike T. Int. Immunol. 3:1217-1221(1991) [PubMed: 1777418] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[6]	"Structure of the human beta2-glycoprotein I (apolipoprotein H) gene." Okkels H., Rasmussen T.E., Sanghera D.K., Kamboh M.I., Kristensen T. Eur. J. Biochem. 259:435-440(1999) [PubMed: 9914524] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[7]	SeattleSNPs program for genomic applications Submitted (JUN-2003) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], VARIANTS ASN-107; HIS-154; LEU-266 AND SER-335.
[8]	"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)." The MGC Project Team Genome Res. 14:2121-2127(2004) [PubMed: 15489334] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Tissue: Liver.
[9]	"Complete amino acid sequence of human plasma beta 2-glycoprotein I." Lozier J., Takahashi N., Putnam F.W. Proc. Natl. Acad. Sci. U.S.A. 81:3640-3644(1984) [PubMed: 6587378] [Abstract] Cited for: PROTEIN SEQUENCE OF 20-345, GLYCOSYLATION AT ASN-162; ASN-183; ASN-193 AND ASN-253, DISULFIDE BONDS.
[10]	"Heterogeneity of anticardiolipin antibodies defined by the anticardiolipin cofactor." Matsuura E., Igarashi Y., Fujimoto M., Ichikawa K., Suzuki T., Sumida T., Yasuda T., Koike T. J. Immunol. 148:3885-3891(1992) [PubMed: 1602135] [Abstract] Cited for: PROTEIN SEQUENCE OF 20-44.
[11]	"Anti-phospholipid antibodies are directed against a complex antigen that includes a lipid-binding inhibitor of coagulation: beta 2-glycoprotein I (apolipoprotein H)." McNeil H.P., Simpson R.J., Chesterman C.N., Krilis S.A. Proc. Natl. Acad. Sci. U.S.A. 87:4120-4124(1990) [PubMed: 2349221] [Abstract] Cited for: PROTEIN SEQUENCE OF 20-43.
[12]	"Purification of apolipoprotein H (beta 2-glycoprotein I)-like protein from human follicular fluid." Aleporou-Marinou V., Pappa H., Yalouris P., Patargias T. Comp. Biochem. Physiol. 128B:537-542(2001) [PubMed: 11250549] [Abstract] Cited for: PROTEIN SEQUENCE OF 20-38. Tissue: Ovarian follicular fluid.
[13]	"Activity, disulphide mapping and structural modelling of the fifth domain of human beta 2-glycoprotein I." Steinkkasserer A., Barlow P.N., Willis A.C., Kertesz Z., Campbell I.D.,