KEGG   ENZYME: 3.2.1.108
Entry
EC 3.2.1.108                Enzyme                                 
Name
lactase;
lactase-phlorizin hydrolase;
LPH (gene name);
LCT (gene name)
Class
Hydrolases;
Glycosylases;
Glycosidases, i.e. enzymes that hydrolyse O- and S-glycosyl compounds
Sysname
lactose galactohydrolase (configuration-retaining)
Reaction(IUBMB)
lactose + H2O = beta-D-galactose + D-glucose [RN:R01100 R06114]
Reaction(KEGG)
R01100 R06114(G);
(other) R01678 R06098(G)
Substrate
lactose [CPD:C00243];
H2O [CPD:C00001]
Product
beta-D-galactose [CPD:C00962];
D-glucose [CPD:C00031]
Comment
The enzyme from intestinal mucosa contains two glycosyl hydrolase domains, both of which belong to glycosyl hydrolase family 1 (GH1). While the first domain catalyses the activity described here, the second domain catalyses the reaction of EC 3.2.1.62 glycosylceramidase. cf. EC 3.2.1.33 amylo-alpha-1,6-glucosidase.
History
EC 3.2.1.108 created 1984, modified 2022
Pathway
ec00052  Galactose metabolism
ec01100  Metabolic pathways
Orthology
K01229  lactase-phlorizin hydrolase
Genes
HSA: 3938(LCT)
PTR: 459633(LCT)
PPS: 100993974(LCT)
GGO: 101136936(LCT)
PON: 100450303(LCT)
NLE: 100602088(LCT)
HMH: 116462849(LCT)
MCC: 707761(LCT)
MCF: 102141036(LCT)
MTHB: 126932258
MNI: 105492565(LCT)
CSAB: 103216991(LCT)
CATY: 105590352(LCT)
PANU: 101022382(LCT)
TGE: 112636379(LCT)
MLEU: 105532195(LCT)
RRO: 104665436(LCT)
RBB: 108539586(LCT)
TFN: 117095069(LCT)
PTEH: 111527488(LCT)
CANG: 105508813(LCT)
CJC: 100408648(LCT)
SBQ: 101044226(LCT)
CIMI: 108293356(LCT)
CSYR: 103263113(LCT)
MMUR: 105857603(LCT)
LCAT: 123643641(LCT)
PCOQ: 105815373(LCT)
OGA: 100944107(LCT)
MMU: 226413(Lct)
MCAL: 110304188(Lct)
MPAH: 110322545(Lct)
RNO: 116569(Lct)
MCOC: 116098602(Lct)
ANU: 117716486(Lct)
MUN: 110555417(Lct)
CGE: 100766856(Lct)
MAUA: 101828124(Lct)
PROB: 127236450(Lct)
PLEU: 114696961(Lct)
MORG: 121446300 121446324 121446359
MFOT: 126504990
AAMP: 119827729 119827814 119827830
NGI: 103734619(Lct)
HGL: 101697396(Lct)
CPOC: 100732160(Lct)
DORD: 105996629(Lct)
DSP: 122110822(Lct)
PLOP: 125350733(Lct)
NCAR: 124980608
OCU: 100009256(LPH) 100352497 100353264
OPI: 101519618 101519868 101520351
TUP: 102470311(LCT)
GVR: 103610021(LCT)
CFA: 483898(LCT)
CLUD: 112649763(LCT)
VVP: 112932617(LCT)
VLG: 121481866(LCT)
NPO: 129503765(LCT)
AML: 100484153(LCT)
UMR: 103667712(LCT)
UAH: 113263420(LCT)
UAR: 123782596(LCT)
ELK: 111143551
LLV: 125095933
MPUF: 101676191(LCT)
NVS: 122902701(LCT)
ORO: 101373825(LCT)
EJU: 114207344(LCT)
ZCA: 113920630(LCT)
MLX: 118012500(LCT)
NSU: 110585741(LCT)
LWW: 102749114(LCT)
FCA: 101092452(LCT)
PYU: 121030495(LCT)
PCOO: 112865772(LCT)
PBG: 122479372(LCT)
LRUF: 124516018
PTG: 102949288(LCT)
PPAD: 109270343(LCT)
PUC: 125911425
AJU: 106969449
HHV: 120230375(LCT)
BTA: 514332(LCT)
BOM: 102279578(LCT)
BIU: 109568203(LCT)
BBUB: 102410227(LCT)
BBIS: 104998486(LCT)
CHX: 102170472(LCT)
OAS: 101104042(LCT)
BTAX: 128043741(LCT)
ODA: 120854489(LCT)
CCAD: 122453560(LCT)
SSC: 100625807(LCT) 100625897
CFR: 102513047(LCT)
CBAI: 105083393(LCT)
CDK: 105092305(LCT)
VPC: 102532468(LCT)
BACU: 103003658(LCT)
LVE: 103074579(LCT)
OOR: 101270599(LCT)
DLE: 111172712(LCT)
PCAD: 102988992(LCT)
PSIU: 116756492(LCT)
NASI: 112412418(LCT)
ECB: 100055369(LCT)
EPZ: 103548925(LCT)
EAI: 106836543(LCT)
MYB: 102246527(LCT)
MYD: 102761793(LCT)
MMYO: 118662079(LCT)
MLF: 102430551(LCT)
MNA: 107531139(LCT)
PKL: 118709739(LCT)
HAI: 109392715(LCT)
DRO: 112313063(LCT)
SHON: 118974532(LCT)
AJM: 119040600(LCT)
PDIC: 114495149(LCT)
PHAS: 123810272(LCT)
MMF: 118625706(LCT)
RFQ: 117025498(LCT)
PALE: 102887366(LCT)
PGIG: 120611943(LCT)
PVP: 105288339(LCT)
RAY: 107511200(LCT)
MJV: 108405363(LCT)
TOD: 119255787(LCT)
SARA: 101545875(LCT)
LAV: 100661599(LCT)
TMU: 101348169
ETF: 101659833(LCT)
DNM: 101441621(LCT)
MDO: 100016393(LCT)
GAS: 123241493(LCT)
SHR: 100933904(LCT)
AFZ: 127554360
PCW: 110223786(LCT)
OAA: 100084941(LCT)
GGA: 424294(LCT)
PCOC: 116227271(LCT)
MGP: 100540699(LCT)
CJO: 107316868(LCT)
TPAI: 128076739 128076758(LCT)
NMEL: 110399364(LCT)
APLA: 101799746(LCT)
ACYG: 106039329(LCT)
AFUL: 116490699(LCT)
TGU: 100229941(LCT)
LSR: 110480639(LCT)
SCAN: 103814626(LCT)
PMOA: 120501755(LCT)
OTC: 121337155(LCT)
PRUF: 121356606(LCT)
GFR: 102041259(LCT)
FAB: 101814034(LCT)
PHI: 102100057(LCT)
PMAJ: 107207677(LCT)
CCAE: 111932317(LCT)
CCW: 104694217(LCT)
CBRC: 103619703(LCT)
ETL: 114057697(LCT)
ZAB: 102069527(LCT)
ACHL: 103797517(LCT)
SVG: 106849901(LCT)
FPG: 101921531(LCT)
FCH: 102058755(LCT)
CLV: 102086420(LCT)
EGZ: 104129535(LCT)
NNI: 104009760(LCT)
PLET: 104616147(LCT)
PCRI: 104026793(LCT)
PCAO: 104053764(LCT)
ACUN: 113482159(LCT)
TALA: 104368387(LCT)
PADL: 103912627(LCT)
AFOR: 103899524(LCT)
ACHC: 115342953(LCT)
HALD: 104323141(LCT)
HLE: 104836526(LCT)
AGEN: 126042537
GCL: 127018545
CCRI: 104157657(LCT)
CSTI: 104559163(LCT)
EHS: 104506311(LCT)
CMAC: 104479709(LCT)
MUI: 104545327(LCT)
BREG: 104640666(LCT)
FGA: 104076580(LCT)
GSTE: 104255215(LCT)
LDI: 104349434(LCT)
MNB: 103775982(LCT)
OHA: 104333255(LCT)
NNT: 104411659(LCT)
SHAB: 115608691(LCT)
DPUB: 104296940(LCT)
PGUU: 104467528(LCT)
ACAR: 104532723(LCT)
CPEA: 104391143(LCT)
AVIT: 104277503(LCT)
CVF: 104287949(LCT)
CUCA: 104065226(LCT)
BRHI: 104488766(LCT)
AAM: 106498455(LCT)
AROW: 112977064(LCT)
NPD: 112948593(LCT)
TGT: 104565650(LCT)
DNE: 112988323(LCT)
SCAM: 104145714(LCT)
ASN: 102370133(LCT)
AMJ: 102576031(LCT)
CPOO: 109323207(LCT)
GGN: 109301357(LCT)
PSS: 102456860(LCT)
CMY: 102946778(LCT)
CPIC: 101933763(LCT)
TST: 117885118(LCT)
CABI: 116826106(LCT)
MRV: 120374328(LCT)
ACS: 103279188(lct)
PVT: 110071879(LCT)
SUND: 121925981(LCT)
PBI: 103054678(LCT)
PMUR: 107284386(LCT)
CTIG: 120307504(LCT)
TSR: 106540054(LCT)
PGUT: 117669655(LCT)
PTEX: 113445465(LCT)
NSS: 113410676(LCT)
VKO: 123027553(LCT)
PMUA: 114604625(LCT)
ZVI: 118092494(LCT)
HCG: 128328212(LCT)
GJA: 107115411(LCT)
STOW: 125426237(LCT)
XLA: 100127248(lct.1.L) 100127291(lct.2.L)
XTR: 100145766(lct.2) 101732850
NPR: 108791336 108791337
RTEM: 120944145 120944146
BBUF: 121008829(LCT) 121008830
BGAR: 122944682 122944685
DRE: 559107 796436(lct)
SRX: 107739717 107741586
SANH: 107688954 107704822
SGH: 107601359 107601360
CAUA: 113108294 113108295
CGIB: 127964591 127964593
PTET: 122351748 122352042
LROH: 127170782 127170873
PPRM: 120485547 120487230
MAMB: 125245778 125245780 125270691
CIDE: 127510573 127519288
MASI: 127447370
IPU: 108266116
PHYP: 113525948(lct)
SMEO: 124380192
TFD: 113654132
AMEX: 103029218(lct)
CMAO: 118807452
EEE: 113577223(lct)
CHAR: 105907898 105907899
TRU: 101076621
LCO: 104939725(lct)
NCC: 104954911(lct)
CGOB: 115026493(lct)
ELY: 117248075 117251770
EFO: 125899187 125899188
PLEP: 121949084 121949085
SLUC: 116044576 116044580
ECRA: 117953249
ESP: 116687473(lct)
PFLV: 114563686 114564430
GAT: 120834464 120834490
PPUG: 119229302
MSAM: 119903852
SCHU: 122885239
CUD: 121522156 121522288 121522602
ALAT: 119025751 119026172
MZE: 101465201 101465483
ONL: 100703330 100703603 100703875 102080755
OAU: 116324944 116324945 116324946 116333422
OLA: 101171223(lct)
OML: 112155270 112155271 112155272
XMA: 102216752 102217013 102223171(lct)
XCO: 114147565 114147571 114147572
XHE: 116722850 116722851 116723643(lct) 116723644
PRET: 103461729
PFOR: 103152094(lct) 103153521
PLAI: 106942509 106945899 106945900
PMEI: 106908439(lct) 106920698
GAF: 122840135 122840136
CVG: 107091021(lct) 107091024
CTUL: 119796496 119796544
GMU: 124870853 124870854
NFU: 107389384(lct)
ALIM: 106522267(lct)
NWH: 119418815
AOCE: 111581081 111586173
MCEP: 125017507 125017508 125017509 125017510 125017511 125017512 125017513
CSEM: 103392433(lct)
POV: 109631322
SSEN: 122759778 122759794
HHIP: 117755058
HSP: 118120062
SDU: 111218818
SLAL: 111667436
XGL: 120801628
HCQ: 109515508(lct)
MALB: 109966332(lct)
BSPL: 114847775
SASA: 106586119(lct)
STRU: 115160641(lct)
OTW: 112235127
OMY: 110519997
OGO: 124043772
ONE: 115107792(lct)
SALP: 111973682(lct)
SNH: 120057744
CCLU: 121536644
ELS: 105005862(lct)
SFM: 108928209(lct)
PKI: 111842887(lct)
AANG: 118222690
LOC: 102691495(lct)
PSPA: 121323070
ARUT: 117407121
PSEX: 120530640
LCM: 102361997(LCT)
CMK: 103180388
RTP: 109919181(lct)
CPLA: 122551934
BBEL: 109468489 109470924
SCLV: 120331019
DSM: 124412459
BGT: 106067751 106069349 106069463
HRF: 124113779 124151882
HRJ: 124256256 124256662 124256664 124266902
CRG: 105317659 117692405
PMAX: 117332095
MCAF: 127712489
MMER: 123533272 123534954
DPOL: 127854839 127854858
TWL: 119987970
 » show all
Reference
1  [PMID:5822067]
  Authors
Asp NG, Dahlqvist A, Koldovsky O.
  Title
Human small-intestinal beta-galactosidases. Separation and characterization of one lactase and one hetero beta-galactosidase.
  Journal
Biochem J 114:351-9 (1969)
DOI:10.1042/bj1140351
Reference
2  [PMID:5010299]
  Authors
Schlegel-Haueter S, Hore P, Kerry KR, Semenza G.
  Title
The preparation of lactase and glucoamylase of rat small intestine.
  Journal
Biochim Biophys Acta 258:506-19 (1972)
DOI:10.1016/0005-2744(72)90242-2
Reference
3  [PMID:5082068]
  Authors
Lorenz-Meyer H, Blum AL, Haemmerli HP, Semenza G.
  Title
A second enzyme defect in acquired lactase deficiency: lack of small-intestinal phlorizin-hydrolase.
  Journal
Eur J Clin Invest 2:326-31 (1972)
DOI:10.1111/j.1365-2362.1972.tb00658.x
Reference
4  [PMID:810166]
  Authors
Ramaswamy S, Radhakrishnan AN.
  Title
Lactase-phlorizin hydrolase complex from monkey small intestine. Purification, properties and evidence for two catalytic sites.
  Journal
Biochim Biophys Acta 403:446-55 (1975)
DOI:10.1016/0005-2744(75)90072-8
Reference
5  [PMID:6786877]
  Authors
Skovbjerg H, Sjostrom H, Noren O.
  Title
Purification and characterisation of amphiphilic lactase/phlorizin hydrolase from human small intestine.
  Journal
Eur J Biochem 114:653-61 (1981)
DOI:10.1111/j.1432-1033.1981.tb05193.x
Reference
6  [PMID:6814489]
  Authors
Skovbjerg H, Noren O, Sjostrom H, Danielsen EM, Enevoldsen BS.
  Title
Further characterization of intestinal lactase/phlorizin hydrolase.
  Journal
Biochim Biophys Acta 707:89-97 (1982)
DOI:10.1016/0167-4838(82)90400-9
Reference
7  [PMID:9762914]
  Authors
Zecca L, Mesonero JE, Stutz A, Poiree JC, Giudicelli J, Cursio R, Gloor SM, Semenza G.
  Title
Intestinal lactase-phlorizin hydrolase (LPH): the two catalytic sites; the role of the pancreas in pro-LPH maturation.
  Journal
FEBS Lett 435:225-8 (1998)
DOI:10.1016/s0014-5793(98)01076-x
Reference
8  [PMID:11106409]
  Authors
Arribas JC, Herrero AG, Martin-Lomas M, Canada FJ, He S, Withers SG.
  Title
Differential mechanism-based labeling and unequivocal activity assignment of the two active sites of intestinal lactase/phlorizin hydrolase.
  Journal
Eur J Biochem 267:6996-7005 (2000)
DOI:10.1046/j.1432-1327.2000.01784.x
Other DBs
ExplorEnz - The Enzyme Database: 3.2.1.108
IUBMB Enzyme Nomenclature: 3.2.1.108
ExPASy - ENZYME nomenclature database: 3.2.1.108
BRENDA, the Enzyme Database: 3.2.1.108
CAS: 9031-11-2
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