Study Of Rat Tripeptidyl Peptidase Ⅰ(TPP-Ⅰ) For Hydrolyzing AngiotensiⅠ,Ⅱ,Ⅲ In Vitro

TPPI is a kind of protin which exists in lysosomes .It can peculiary dewmpose oligomycin and protin N-terminus and release kyrine .The genes of TPPI exist in chomesome 11p15 of human body,containing 13 exon and 12 intron. It is 6.65 kb long coding 563 amino acid residue.TPPI is the morbid protein of CLN2.Because of the mutation of gene mutation of TPPI,the bioblast of ATP synthetase's subunit C accumulate with a huge number.1. The origin of TPPIIn organism,the decomposition of protein is necessary for the living and death of a cell.In the way of dewmposition and metabolization,the protein'shydrdytic and deyradation the proteins inside of them to snippet of tai with different length according to their quality and location,And then hydrolytic it to aminoacid,supplying the next step of the wmbination of protein.Among them,the one which can dewmpose protein or polypeptide to three tai's protein is TPPI[1,2].So far,it is discovered that there are two kinds of TPPIS in orgnism,the TPPIⅠ[2] and TPPIⅡ[3].They exist in lysosomes and cytoplasm respectively.These two kinds of enzymes have different physicochemical property,sensitivity for catastaltic and location.TPPI was discovered by Ellis and his colleague in 1961,and was given name by McDonald JK and so on In 1985.In 1992 it was given the name TPPI for mally(EC 3.4.14.9).TPPIⅡis a macrolecular protein,molecular mass is 138KD,it exists in cytoplasm and it is a kind of serinase[6],TPPI's cDNA sequence had been made clear[7].2. The physicochemical property of TPPITPPI can peculiary decompose oligomycin and protein's N-terminus and realease kyrine[1], Ala-Ala-Phe,Ala-Phe-Pro,Gly-Pro-Ala,Gly-Pro-Met[3,9]. It does not only exit in microbe,but also extensively in mamal and human body,just as pituitary[3],oophoras[2],osteoclast nodule[9],the white rat's milt[10],liver[11],cow's brain tissue[12] and so on.It molecular weight is 47-67KD[1,2,9,10,12,13-15],The suit PH is acidity[9,10,14],the suit temperature is 37℃, It can be in active at 50℃and deavtivation in freeze[14].It is indecated by the research of catastaltic sensitivity,it is strongly pent-up by Hg2+ and DFP[2,14],So , it is a kind of serinase which is regulation by sulfhydryl reagent.The genes of human's TPPI exist in chromosome 11p15,containing 13 exon and 12 intron,it's length is 6.65Kb,coding 563 amino acid residue,and the precursor protein of code of gene is not active.After severted by Golgi complex to lysosomes,In the acid enviroment of lysosomes,it lysis automatically into TPPI[16-18].Through the analysis by Northern blot,TPPI's Mana has two forms, the form of 2.5kb and the form of 3.0kb.That's because different organization have different length of mRNA's 3'-bottom uncode in one organism[18].Among them,the transcript of the 2.5kb from mainly exist in heart,liver,kidany,lungs and spleen,whereas the transcript of 3.0kb form mainly exist in brain. This result shows that TPPI scattered in every viscera of the big mice and the TPPI express in kidnay,liver and heart remarkablely and express in spleen,brain and lung with middle extent,and express in skeletal muscle and testis infermly.This result match the result of immunohistochemical method dying and enzymic activity analysis[19].3. Biological functionThis research indicates that TPPI can peculiarly decompose oligomycin and protein's N-terminus and release kyrine and the kyrine which is released can be further devomoposed to amino acid by dipeptidase and aminopeptidase[20] .Now the research indicates that TPPI's mainly phisiological function is decomposition collagenⅠ[2,9].So it has something to do with bone multiple absorption.Moreover,it can aspiration Ca2+ into blood[10] and decompose angiotensinⅠand dyophin and such materials which have physidogical active[10,12,15].The futher research indicates that,the mutation of the game of TPPI cause (CLN2)[18,21].CLN2 is a kind of hereditary neural degeneration.Based on the age it occurs,the clinical pathology and the chromosomal localization,This kind of disease is characterized by its occurance in children period,containing CLN1,CLN2,CLN3,CLN5,CLN6 and CLN7.Among them,the cause of CLN1,CLN2 and CLN3 have alrealdy been made clear.Laster,Sleat[6] and some other people have identified an unique who died of CLN2 by composing a kind of soluble lysosomal enzymes which contains mannose–6-phosphate.The kind of protein is just a kind of lysosomal proteinase which is sensitive to gastrin.Vines and warburton reported the sequence of TPPI's three hydrolytic fragment's amino acid.Rawling and Barrett analysized the sequence of the above three hydrolytic fragment's amino acid by the use of data base.Vines and Warburton[3] also reported that TPPI and the gastrin -no sensitivity which sevrete by CLN2 are identical.And the patients of CLN2's fiber balstcell is lack of TPPI .They also discovered that there are higher accumulation of cell pigment C in the bioblast ATD of the patients of CLN2.The immune exclude experiment of lososome TPPI which comes from ordinary cutis fiber blast cell shows that the ability of decomposition of cell pigment decreased and is speed of compose is normal[23,24].So we can think that cell pigment C may be naturally matrix of TPPI .Koike[25] and other people reported that the CNS Subunitc of little mice which is lack of cathepsin firstly decomposed by TPPI,and then they are further decomposed by cathepsin D. So we know that there are lots of evidences that TPPI is morbid protein of CLN2.The mutation of TPPI's genes makes the accumulation of ATP synthetase Subunit C in lysosomes ,and makes the nerve and other cells which produce fluorescent matter and then be taken bad.Clinical syndrome:the obstacle of visual sense,the abnormal accutiving and convulsion.It occurred mainly in Australia ,and has not been discovered in our country.To summarise, the function and bioactivity of TPPI need to be further and more extensive research.If we want to study its biological function .We must gene to unchain the experiment of little mice and establish the endohormone of CLN2,and then we can thotoughly discover its function in bodies.