Basic Information | Overview of PTM Sites | Experimental PTM Sites | Protein-Protein Interactions | Drug and Disease Associations | Related Literatures
Basic Information
Protein Name :  Plasma serine protease inhibitor  

UniProtKB / Swiss-Prot ID :  IPSP_HUMAN

Gene Name (Synonyms) : 
SERPINA5, PCI, PLANH3, PROCI  

Species :  Homo sapiens (Human). 

Subcellular Localization :  Secreted, extracellular space. Note=Localized on the plasma membrane overlying the acrosomal head of spermatozoa of ependymal spermatozoa and ejaculated sperm. Localized at the equatorial segment of acrosome-reacted spematozoa. Localized in alpha granule 

Protein Function :  Heparin-dependent serine protease inhibitor acting in body fluids and secretions. Inactivates serine proteases by binding irreversibly to their serine activation site. Involved in the regulation of intravascular and extravascular proteolytic activities. Plays hemostatic roles in the blood plasma. Acts as a procoagulant and proinflammatory factor by inhibiting the anticoagulant activated protein C factor as well as the generation of activated protein C factor by the thrombin/thrombomodulin complex. Acts as an anticoagulant factor by inhibiting blood coagulation factors like prothrombin, factor XI, factor Xa, plasma kallikrein and fibrinolytic enzymes such as tissue- and urinary- type plasminogen activators. In seminal plasma, inactivates several serine proteases implicated in the reproductive system. Inhibits the serpin acrosin; indirectly protects component of the male genital tract from being degraded by excessive released acrosin. Inhibits tissue-and urinary-type plasminogen activator, prostate-specific antigen and kallikrein activities; has a control on the sperm motility and fertilization. Inhibits the activated protein C-catalyzed degradation of SEMG1 and SEMG2; regulates the degradation of semenogelin during the process of transfer of spermatozoa from the male reproductive tract into the female tract. In urine, inhibits urinary-type plasminogen activator and kallikrein activities. Inactivates membrane-anchored serine proteases activities such as MPRSS7 and TMPRSS11E. Inhibits urinary-type plasminogen activator-dependent tumor cell invasion and metastasis. May also play a non-inhibitory role in seminal plasma and urine as an hydrophobic hormone carrier by its binding to retinoic acid. 

Protein Sequence MQLFLLLCLVLLSPQGASLHRHHPREMKKRVEDLHVGATVAPSSRRDFTFDLYRALASAAPSQSIFFSPV...
Predicted Secondary Structure CHHHHHHHHHHCCCCCCCCCCCCCCCCCCCCCCCCCCHHHHHHHHHHHHHHHHHHHHHHCCCCCEEECCH...
Protein Variant
LocationDescription
44S -> G (in dbSNP:rs2069975). VAR_013080
55A -> V (in allele PCI*B; dbSNP:rs6118). VAR_007100
64S -> N (in dbSNP:rs6115). VAR_013081
94G -> V (in dbSNP:rs2069976). VAR_013082
105K -> E (in allele PCI*B; dbSNP:rs6119). VAR_007101
115L -> P (in dbSNP:rs2069999). VAR_013083
121P -> A (in dbSNP:rs6120). VAR_013900
217G -> R (in dbSNP:rs6114). VAR_013084
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Overview of Protein Modification Sites with Functional and Structural Information
Accessible Surface Area (ASA)
Pred. Secondary
Real Secondary
Disorder Prediction
Protein Domain
&
Experimental PTM Sites
Predicted PTM Sites
Protein Variant
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Experimental Post-Translational Modification Sites Download
Locations
Modification
Substrate Sites
&
Secondary Structure
Accessible Surface Area (%)
Resource
Reference
Structural Characterization
Orthologous
Protein Cluster
39O-linked (GalNAc...).HVGATVAPS
CCCHHHHHH
15.98UniProtKB
Link-
249N-linked (Glc...)LLDRNLSCR
EEECCCCCE
35.65HPRD
Link
249N-linked (GlcNAc...).LLDRNLSCR
EEECCCCCE
35.65UniProtKB
Link
262N-linked (Glc...)PYQGNATAL
EECCCEEEE
20.70HPRD
Link
262N-linked (GlcNAc...).PYQGNATAL
EECCCEEEE
20.70UniProtKB
Link
338N-linked (Glc...)SGISNHSNI
CCCCCCCCE
40.46HPRD
Link
338N-linked (GlcNAc...).SGISNHSNI
CCCCCCCCE
40.46UniProtKB
Link
373noneIFTFRSARL
EEEEECCCC
26.75HPRD
Link-
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Protein-Protein Interactions
      Interacting Protein      
Interaction type
Source ID
      Resource      
      Pubmed ID      
Domain-Domain Interactions
CSN6_HUMANphysical interactionMINT-63402MINT16169070
CSN6_HUMANphysical interactionEBI-735763
intact16169070
FIBA_HUMANin vitroHPRD:03503HPRD8589203
8384496
FIBB_HUMANin vitroHPRD:03503HPRD8148485
8384496
FIBG_HUMANin vitroHPRD:03503HPRD8384496
KLK1_HUMANin vitroHPRD:03503HPRD9368023
TPA_HUMANin vivoHPRD:03503HPRD2551064
KLK3_HUMANin vitroHPRD:03503HPRD7509746
8665956
8732755
PROC_HUMANin vitroHPRD:03503HPRD11123896
THRB_HUMANin vitroHPRD:03503HPRD12878585
TRBM_HUMANin vitroHPRD:03503HPRD12878585
UROK_HUMANin vitro
in vivo
HPRD:03503HPRD2752144
9365930
FA10_HUMANin vitroHPRD:03503HPRD2551064
KLKB1_HUMANin vitroHPRD:03503HPRD11864713
2551064
SEMG2_HUMANin vitroHPRD:03503HPRD8665956
IPSP_HUMANin vitroHPRD:03503HPRD12575940
CSN6_HUMANyeast 2-hybridHPRD:03503HPRD16169070
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Disease Reference
Kegg disease
There are no disease associations of PTM sites.
Drug Reference
DrugBank
DB00055Drotrecogin alfa
DB00013Urokinase
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Related Literatures of Post-Translational Modification
N-linked Glycosylation
ReferencePubMed
"Screening for N-glycosylated proteins by liquid chromatography massspectrometry.";
Bunkenborg J., Pilch B.J., Podtelejnikov A.V., Wisniewski J.R.;
Proteomics 4:454-465(2004).
Cited for: GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-249, AND MASSSPECTROMETRY.
"Human plasma N-glycoproteome analysis by immunoaffinity subtraction,hydrazide chemistry, and mass spectrometry.";
Liu T., Qian W.-J., Gritsenko M.A., Camp D.G. II, Monroe M.E.,Moore R.J., Smith R.D.;
J. Proteome Res. 4:2070-2080(2005).
Cited for: GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-262 AND ASN-338, AND MASSSPECTROMETRY.
"N-glycans and the N terminus of protein C inhibitor affect thecofactor-enhanced rates of thrombin inhibition.";
Sun W., Parry S., Panico M., Morris H.R., Kjellberg M., Engstrom A.,Dell A., Schedin-Weiss S.;
J. Biol. Chem. 283:18601-18611(2008).
Cited for: FUNCTION, PROTEOLYTIC CLEAVAGE, GLYCOSYLATION AT ASN-249; ASN-262 ANDASN-338, STRUCTURE OF CARBOHYDRATES, SUBCELLULAR LOCATION, TISSUESPECIFICITY, AND MASS SPECTROMETRY.
"Crystal structure of protein C inhibitor provides insights intohormone binding and heparin activation.";
Huntington J.A., Kjellberg M., Stenflo J.;
Structure 11:205-215(2003).
Cited for: X-RAY CRYSTALLOGRAPHY (2.4 ANGSTROMS) OF 30-406, AND GLYCOSYLATION ATASN-262.
O-linked Glycosylation
ReferencePubMed
"Further insight into the roles of the glycans attached to human bloodprotein C inhibitor.";
Sun W., Parry S., Ubhayasekera W., Engstrom A., Dell A.,Schedin-Weiss S.;
Biochem. Biophys. Res. Commun. 403:198-202(2010).
Cited for: GLYCOSYLATION AT THR-39, AND MASS SPECTROMETRY.
"Human urinary glycoproteomics; attachment site specific analysis ofN-and O-linked glycosylations by CID and ECD.";
Halim A., Nilsson J., Ruetschi U., Hesse C., Larson G.;
Mol. Cell. Proteomics 0:0-0(2011).
Cited for: GLYCOSYLATION AT THR-39, STRUCTURE OF CARBOHYDRATES, AND MASSSPECTROMETRY.
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Basic Information | Overview of PTM Sites | Experimental PTM Sites | Protein-Protein Interactions | Drug and Disease Associations | Related Literatures