[Cysteine cathepsins: structure, physiological functions and their role in carcinogenesis]. / Tsisteinovye katepsiny: stroenie, fiziologicheskie funktsii i rol' v kantserogeneze.

Cysteine cathepsins (Cts) also known as thiol proteinases belong to the superfamily of cysteine proteinases (EC 3.4.22). Cts are known as lysosomal proteases responsible for the intracellular proteins degradation. All Cts are synthesized as zymogens, activation of which occurs autocatalytically. Their activity is regulated by endogenous inhibitors. Cts can be secreted into the extracellular environment, which is of particular importance in tumor progression. Extracellular Cts not only hydrolyze extracellular matrix (ECM) proteins, but also contribute to ECM remodeling, processing and/or release of cell adhesion molecules, growth factors, cytokines and chemokines. In cancer, the expression and activity of Cts sharply increase both in cell lysosomes and in the intercellular space, which correlates with neoplastic transformation, invasion, metastasis and leads to further tumor progression. It has been shown that Cts expression depends on the cells type, therefore, their role in the tumor development differs depending on their cellular origin. The mechanism of Cts action in cancer is not limited only by their proteolytic action. The Cts influence on signal transduction pathways associated with cancer development, including the pathway involving growth factors, which is mediated through receptors tyrosine kinases (RTK) and various signaling mitogen-activated protein kinases (MAPK), has been proven. In addition, Cts are able to promote the epithelial-mesenchymal transition (EMT) by activating signal transduction pathways such as Wnt, Notch, and the pathway involving TGF-ß. So, Ctc perform specific both destructive and regulatory functions, carrying out proteolysis, both inside and outside the cell.

[The expression of EMMPRIN and the matrix metalloproteinase MMP-1 in the cervix uteri and corpus uteri in cervical squamous cell carcinoma]. / Ékspressiia EMMPRIN i matriksnoi metalloproteinazy MMP-1 v sheike i tele matki pri tservikal'noi ploskokletochnoi kartsinome.

OBJECTIVE: To investigate the features of expression of extracellular matrix metalloproteinase inducer (EMMPRIN) and the matrix metalloproteinase MMP-1 in the cervix uteri and corpus uteri in cervical squamous cell carcinoma (CSCC). MATERIAL AND METHODS: The investigation was conducted using the surgical material obtained after hysterectomy in patients diagnosed as having CSCC. RT-PCR, immunohistochemistry (IHC), and enzymatic assays were used. RESULTS: The high expression of EMMPRIN and MMP-1 in CSCC was found not only in cervical carcinoma, but also in the stroma and epithelium of the cervix uteri and corpus uteri outside the tumor, whereas the level of MMP-1 expression in the morphologically intact tissue was significantly lower than in the tumor, while that of EMMPRIN gene expression did not differ substantially. CONCLUSION: The expression of EMMPRIN and MMP-1 in CSCC occurs in both the tumor and the morphologically intact tissue, which may suggest that the invasive potential of tumor may increase and therefore have prognostic value.

[Gelatinases A and B and their endogenous regulators in the corpus uteri in squamous cell cervical carcinoma]. / Zhelatinazy A i V i ikh éndogennye reguliatory v tele matki pri ploskokletochnoi kartsinome sheiki matki.

OBJECTIVE: To investigate the expression of gelatinases A and B (matrix metalloproteinases (MMP 2 and MMP 9) and endogenous regulators of their activity, such as a tissue inhibitor of MMP - TIMP-2 and a Pro-MMP-9 activator - urokinase-type plasminogen activator (uPA) as factors of corpus uteri invasion in squamous cell cervical carcinoma (SCCC). MATERIAL AND METHODS: The surgical material obtained after hysterectomy in patients diagnosed with SCCC was examined. RT-PCR, immunohistochemistry (IHC), and enzyme-linked immunosorbent assay were used. RESULTS: In SCCC, the expressions of MMP 2 and MMP 9 were found to be high not only in carcinoma of the cervix uteri but also in the corpus uteri, which makes an additional contribution to the enhanced invasive potential of tumors and may have a prognostic value. In SCCC, the expression of MMP 9 may be induced in the corpus uteri where it was absent in normal conditions. MMP 9 can serve as a marker of an invasive process. In most cases, the activity of uPA in the tumor was significantly higher than that in intact uterine tissue, and the expression of TIMP-2 did not change substantially along the entire length of a tissue band (from the vaginal wall to the uterine fundus), as evidenced by RT-PCR, and was at a low level or absent, as shown by IHC. Impaired regulation of MMP 2 and MMP 9 expressions was found not only at the gene level, but also at post-translational one. CONCLUSION: The expression of the gelatinases MMP 2, MMP 9 and regulators of their activity is aimed at increasing the tumor destructive (invasive) potential and can occur (be induced) in the intact corpus uteri tissue that is morphologically different from cervix uteri tissue with apparent participation of signaling through an epithelial-mesenchymal interaction. The induced MMP 9 can serve as a marker for invasive potential. The data indicate different tissue functions of MMP 2 and MMP 9. They are important for understanding the role of the gelatinases MMP 2, MMP 9 during carcinogenesis, can have a prognostic value, and affect a therapeutic strategy for patient management.

[The urokinase-type plasminogen activator system and its role in tumor progression]. / Rol' sistemy aktivatora plazminogena urokinaznogo tipa v progressii opukholei.

In the multistage process of carcinogenesis, the key link in the growth and progression of the tumor is the invasion of malignant cells into normal tissue and their distribution and the degree of destruction of tissues. The most important role in the development of these processes is played by the system of urokinase-type plasminogen activator (uPA system), which consists of several components: serine proteinase - uPA, its receptor - uPAR and its two endogenous inhibitors - PAI-1 and PAI-2. The components of the uPA system are expressed by cancer cells to a greater extent than normal tissue cells. uPA converts plasminogen into broad spectrum, polyfunctional protease plasmin, which, in addition to the regulation of fibrinolysis, can hydrolyze a number of components of the connective tissue matrix (СTM), as well as activate the zymogens of secreted matrix metalloproteinases (MMР) - pro-MMР. MMРs together can hydrolyze all the main components of the СTM, and thus play a key role in the development of invasive processes, as well as to perform regulatory functions by activating and releasing from STM a number of biologically active molecules that are involved in the regulation of the main processes of carcinogenesis. The uPA system promotes tumor progression not only through the proteolytic cascade, but also through uPAR, PAI-1 and PAI-2, which are involved in both the regulation of uPA/uPAR activity and are involved in proliferation, apoptosis, chemotaxis, adhesion, migration and activation of epithelial-mesenchymal transition pathways. All of the above processes are aimed at regulating invasion, metastasis and angiogenesis. The components of the uPA system are used as prognostic and diagnostic markers of many cancers, as well as serve as targets for anticancer therapy.

[Interstitial collagenase and their endogenous regulators in squamous cell cervical carcinoma]. / Interstitsial'naia kollagenaza MMP-1 i ee éndogennye reguliatory v tele matki pri ploskokletochnoi kartsinome sheiki matki.

Interstitial collagenase (MMP-1) belongs to the family of matrix metalloproteinases (MMP), which play a key role in generalization processes of invasion and metastasis, which determine the degree of tumor malignancy. MMP-1 refers to secreted, inducible MMP, the expression of which in normal tissues is not defined. Induction of expression of MMP in CSS in the tumor occurs under the action of oncogenes of HPV, and in areas adjacent to the tumor normal tissue under the action of the inductor expression of MMP - EMMPRIN (CD147), which expressively on the surface of tumor cells. The aim of this study is to determine the possibility of expression ofMMP-1 and its regulators (tissue inhibitors TIMP-1 and activator - plasminogen activator - ADF) in morphologically normal body of the uterus during CSS. The study was carried out using on a tissue "tape" - postoperative specimens of the uterus when the diagnosis of CSS. All of the samples was expressed HPV16 gene E7. It was shown that: 1. The increase of MMP-1 expression, low expression (or lack thereof) of its inhibitors TIMP-1 and a very clear expression of the activator take place in the tumor when CSS that lead to increased activity of MMP-1, and aims to increase the destructive (invasive) potential of the tumor. 2. In morphologically normal tissue of the uterus during CSS the expression of MMP-1 can occur from the vaginal wall to the bottom of the uterine cavity, but at a much lower level than in the tumor. 3. These data indicate the possibility of development of a destructive process in morphologically normalnyh body tissues of the uterus during CSS, important for understanding the mechanism of tumor progression, and suggest participation in the process of expression of MMP-1 signaling by the type of epithelial-mesenchymal interaction .

[Tissue collagenase MMP-14 and endogenous regulators of its activity in the corpus uteri in squamous cell carcinoma of the cervix]. / Tkanevaia kollagenaza MMP-14 i éndogennye reguliatory ee aktivnosti v tele matki pri ploskokletochnoi kartsinome sheiki matki.

AIM: to investigate the expression of the membrane-bound matrix metalloproteinase MT1-MMP (MMP-14), its tissue inhibitor TIMP-2, and the proMMP-14 activator furin in the corpus uteri from the vaginal wall to the bottom of the uterine cavity in squamous cell carcinoma of the cervix (SCCC). MATERIAL AND METHODS: Hysterectomy material was examined in patients with SCCC. Reverse transcriptase polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and enzyme assays were used. RESULTS: In SCCC, higher levels of MMP-14 expression were established in tumor cells, as evidenced by IHC (+3) and RT-PCR. IHC showed that the expression of MMP-14 was absent or insignificant in the normal uterine endometrial and myometrial tissues. However, that of MMP-14 mRNA was also found in the normal tissues to the bottom of the uterine cavity. Furin activity in the tumor was much higher than that in normal tissues. IHC indicated that TIMP-2 expression was low or absent in both the tumor and normal tissues. The expression of TIMP-2 mRNA was sufficiently obvious in both the tumor and normal tissues to the bottom of the uterine cavity. CONCLUSION: In SCCC, MMP-14 expression was substantially increased in tumors. The expression of MMP-14 and regulators of its activity is aimed at enhancing the tumor destructive (invasive) potential in the pericellular space and can occur (be induced) in the morphologically normal uterine tissue apparently with involvement of signaling through the epithelial-mesenchymal interaction. Data are important for understanding the role of MMP-14 in the development of a multistage process of carcinogenesis and may have prognostic value and an impact on therapeutic strategy for the patient.

[Furin as proprotein convertase and its role in normaland pathological biological processes]. / Furin kak proproteinkonvertaza i ego rol' v normal'nykh i patologicheskikh biologicheskikh protsessakh.

Furin belongs to serine intracellular Ca2+-dependent endopeptidases of the subtilisin family, also known as proprotein convertase (PC). Human furin is synthesized as zymogen with a molecular weight of 104 kDà, which is then activated by autocatalytic in two stages. This process can occur when zymogen migrates from the endoplasmic reticulum to the Golgi apparatus, where a large part of furin is accumulated. The molecular weigh t of the active furin is 98 kDà. Furin relates to enzymes with a narrow substrate specificity: it hydrolyzes peptide bonds at the site of paired basic amino acids and furin activity exhibits in a wide pH range 5-8. Its main biological function is activation of the functionally important protein precursors. It is accompanied by the launch of a cascade of reactions, which lead to appearance of biologically active molecules involved in realization of specific biological functions both in normal and in some patologicheskih processes. Furin substrates are biologically important proteins such as enzymes, hormones, growth factors and differentiation, receptors, adhesion proteins, proteins of blood plasma. Furin plays an important role in the development of processes such as proliferation, invasion, cell migration, survival, maintenance of homeostasis, embryogenesis, as well as the development of a number of pathologies, including cardiovascular, oncologic and neurodegenerative diseases. Furin and furin-like proprotein convertases participate as key factors in the realization of the regulatory functions of proteolytic enzymes, the value of which is currently being evaluated as most important in comparison with the degradative function of proteases.

[Matrix metalloproteinases and their endogenous regulators in squamous cervical carcinoma (review of the own data)].

Expression of matrix metalloproteinases (MMPs) and their endogenous regulators has been investigated in squamous cervical carcinoma (SCC). The study included (i) immortalized fibroblasts (IF) and three clones of fibroblasts transformed by oncogene E7 HPV-16 (TF); (ii) cell lines associated with HPV-16 and HPV-18; (iii) tumor tissue samples from patients with SCC, associated with gene E7 HPV-16. Transfection of fibroblasts with the E7 HPV16 oncogen was accompanied by induction of collagenase (MMP-1, MMP-14) and gelatinase (MMP-9) gene expression and the increase in catalytic activity of these MMP, while gelatinase MMP-2 expression remained unchanged. Expression of MMP-9 was found only inTF. MMP-9 may serve as a TF marker. In TF expression mRNA TIMP-1 was decreased. The level of free endogenous inhibitors in TF was significantly lower then the level in IF. Expression MMP correlated with the tumorigenic potential of TF. Invasive potential of cell lines associated with HPV18 (HeLa and S4-1) was more pronounced than that of cell lines associated with HPV16 (SiHa and Caski). The cell lines differed substantially in the level of expression of MMPI and their endogenous regulators. In most cell lines mRNA levels of collagenases MMP-1 and MMP-14 and the activator (uPA) increased, while gelatinase MMP-2 mRNA and tissue inhibitors mRNAs changed insignificantly. MMP-9 expression in cell lines was not detected. Results of studies on these cell lines suggest existence of an imbalance in the system enzyme/inhibitor/activator, that increases destructive potential of these cells. The study of expression of MMP and their endogenous regulators performed using SCC tumor samples associated with HPV16 has shown that the invasive and metastatic potentials of tumor tissue in SCC is obviously determined by the increase of expression of collagenases MMP-1, MT1-MMP and gelatinase MMP-9, decreased expression of inhibitors (TIMP-1 and TIMP-2), and to a lesser extent to increased expression of MMP-2. MMP-1 and MMP-9 can serve as markers of invasive and metastatic potential of the SCC tumor. In adjacent to the tumor normal tissue revealed a significant expression of MMP-1,-2,-9.

[Matrix metalloproteinases 2 and 9, their endogenous regulators, and angiotensin-converting enzyme in cervical squamous cell carcinoma].

OBJECTIVE: to investigate the specific features of the expression of matrix metalloproteinases 2 and 9 (MMP-2, MMP-9), tissue inhibitor of metalloptoteinase 2 (TIMP-2), urokinase-type plasminogen activator (uPA), and angiotensin-converting enzyme (ACE) in cervical squamous cell carcinoma (CSCC). MATERIAL AND METHODS: The samples of tumor tissue and morphologically normal tissue adjacent to the tumor were investigated. Enzymatic assays applying specific substrates, as well as zymographic and immunohistochemical studies were used. RESULTS: The invasive potential of CSCC has been established to be substantially influenced by the increased expression of MMP-9 and uPA and by the decreased expression of TIMP-2, as well as to a lesser extent by a change in MMP-2 expression. MMP-9 may serve as a marker for invasive growth. Enhanced ACE activity in cancer confirms the involvement of this enzyme in tumor progression. The morphologically normal tissue adjacent to the tumor shows the substantial expression of MMP-2 and MMP-9 and in some cases the enhanced activity of uPA and ACE, which makes an additional contribution to the increased invasive potential of tumor. CONCLUSION: The findings are important in understanding the mechanisms of cancer progression and may affect therapeutic strategies for the patient.

[Membrane type 1 matrix metalloproteinase (MT1-MMP) and the regulators of its activity as invasive factors in squamous cell cervical carcinomas].

Membrane type 1 matrix metalloproteinase (MT1MMP) is one of matrix metalloproteinases (MMP), which play а key role in tumor invasion and metastasis. The aim of this study was to elucidate the peculiarities of expression of MT1MMP and endogenous regulators of its activity: the activator - furin and the inhibitor - TIMP-2, as invasive factors of squamous cell cervical carcinomas (SCC). The study was carried out using 11 specimens of SCC and 11 specimens of morphologically normal tissue adjacent to the tumor. It was shown that the increase of MT1-MMP and furin expression and low of TIMP-2 expression makes the main contribution to the destructive (invasive) potential of SCC. Moreover, substantial expression of MT1-MMP was registered in the specimens of morphologically normal adjoining to tumor tissue. This expression was found to make an additional contribution to the destructive potential of the cervical tumor.

[Expression of gelatinases A and B and their endogenous regulators in immortal and transformed fibroblasts].

Matrix metalloproteinases (MMP) play a critical role in tumor invasion and metastasis. The aim of this study was to elucidate peculiarity of expression of gelatinases A and B (MMP-2 and MMP-9), membrane type MMP (MT1-MMP) and tissue inhibitor of MMP (TIMP-2) in immortal (IF) and transformed fibroblasts (TF).The study was carried out using embryo rat fibroblasts, sequentially immortalized with the polyomavirus LT gene and transformed with the E7 gene of human papilloma virus (HPV-16). Papilloma virus type 16 and 18 are etiological factors of cervical cancer. The primary fibroblast (PF) culture of Fisher rats was used as control. Analysis of TF and IF involved: determination of MMP-2 and MMP-9 activity by hydrolysis of specific substrate--radioactive collagen type IV; obtaining of MMP spectra by zimographic assay and estimation of the mRNA expression (by RT-PCR) of MMP-2, MMP-9, MT1- MMP and TIMP-2. It was found: 1) collagenolytic activity of MMP was increased only in TF and was dependent on the degree of cell tumorogenity; 2) the study of MMP spectra was shown that MMP-9 was found in TF only but MMP-2 was found in all investigated clones; 3) The mRNA expression of MMP-9, MT1-MMP and TIMP-2 was increased in all TF while the MMP-2 expression was increased in TF only after TF cell selection on rats; 4) The collagenolytic activity as well as the mRNA expression of MMP-2 and MMP-9 themselves and of MMP-2 endogenous regulators (MT1-MMP and TIMP-2) did not change in immortalized fibroblasts compared to PF. The data obtained indicate changes in the enzyme/inhibitor/activator ratio and also suggest of a significant increase in the TF destructive potential. MMP-9 is supposed to be a marker of fibroblasts transformed by E7 HPV-16 gene in cell culture.

[Expression of interstitial collagenase and its endogenous regulators in immortalized and transformed by E7 gene HPV16 fibroblasts].

Matrix metalloproteinases (MMPs) play a critical role in tumor development and invasion. The aim of this study is to elucidate peculiarity of expression of interstitial collagenase (MMP-1) and its endogenous regulators in the process of oncogenic transformation of fibroblasts by E7 gene of HPV16. Papilloma virus type 16 and 18 are aetiological factor of cervical cancer. We have studied expression of MTI-MMP, MMP-1, tissue inhibitor of these proteases TIMP-1 and urokinase-typeplasminogen activator (uAP). The study was carried out using fibroblasts immortalized by LT gene (IF) and transformed by E7 gene of HPV-16 fibroblasts (TF). Primary culture of Fisher rat embryo fibroblasts was used as a control (PF). mRNA expression was studied by RT-PCR, enzymatic activity--by hydrolysis of fluorogenic type I collagen. It was found that cell transformation is accompanied by: a) 2-3 fold induction of MT1-MMP mRNA expression (vs PF); b) the decrease in mRNA level of TIMP-1 (1,5-2 fold); c) unchanged uPA expression. Cell immortalization is accompanied by: a) the increase of MT1-MMP expression (1,5-2 fold); b) unchanged TIMP-1 expression; c) the increase of uPA expression (2-4 fold) (vs PF and TF). MMP secreted activity and activity in lysates of TF increased but the level of free endogenous MMP inhibitors decreased (vs IF). Data on gene expression are consistent with enzymatic data on the collagenolytic activity. These results suggest changes in enzyme/inhibitor/activator ratio both TF and IF and significant enhancement of the destructive potential of the TF.

[Study of substrate specificity of a new peptide substrate of endothelin converting enzyme].

The new fluorogenic hexapeptide substrate CMC-Ala-Gly-Gly-Trp-Phe-Arg was used as substrate for endothelin-converting enzyme (ECE), angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP). The specific inhibitors lisinopril (ACE) and thiorphan (NEP) were used for identification of these enzyme activities,

[Characterization of cysteine proteinase endogenous inhibitors obtained from transformed fibroblasts]. / Kharakteristika éndogennykh ingibitorov tsiteinovykh proteinaz iz transformirovannykh fibroblastov.

The thermostable endogenous cysteine proteinase inhibitors (CPI) from the primary (REF), immortal (clone IE5) and transformed (clones trF8 and trF8nmcc) fibroblasts were isolated. All the isolated CPI act as reversible competitive inhibitors of cathepsins B and L and of papain. The study of inhibition of cathepsins B and L, purified from the same cell cultures as the CPI, showed that the Ki values for CPI from the cultures of immortal and transformed cells were by one order higher than the Ki values for CPI of primary fibroblasts. The data obtained suggest that immortalization and transformation alter the CPI properties.

Expression of cathepsin L and its endogenous inhibitors in immortal and transformed fibroblasts.

METHODS: The activities of cathepsin L and its endogenous inhibitors were analyzed in rat embryo fibroblasts, immortalized and transformed by different genes. RESULTS: Regardless of the transfecting agent used (DNA of adenovirus SA7 or polyomavirus LT gene), the immortal cells showed an increase in the cathepsin L activity (in both lysates and conditioned media) compared to primary fibroblasts. Transformed cells exhibited either an increase (with c-Ha-ras gene) or decrease (with E7 HPV gene) in cathepsin L activity in lysates as opposed to immortal cells. CONCLUSIONS: The data are suggestive of alterations in the trafficking of cathepsin L upon fibroblast transfection with polyomavirus LT gene and E7 HPV gene. An endogenous inhibitor(s) of cysteine proteinase was found in conditioned media, but not in lysates, of all cell cultures studied and its activity in normal fibroblasts was higher than in media of immortal and transformed cells.

[Type I and IV collagenases and their endogenous regulators in immortalized and transformed fibroblasts]. / Kollagenazy I i IV tipov i ikh éndogennye reguliatory v immortalizirovannykh i transformirovannykh fibroblastakh.

To elucidate the role of matrix metalloproteinases (MMP) in carcinogenesis, the expression of collagenases of types I (MMP-I) and IV (MMP-2 and MMP-9) as well as the behaviour of urokinase-like plasminogen activator (uPA) and of tissue MMP inhibitors (TIMP) in immortalized (IF) and transformed (TF) fibroblasts were investigated. The study was carried out using embryo rat fibroblasts, sequentially immortalized with the LT gene of human papilloma virus and transformed with the E7 gene of human papilloma virus (HPV-16). As control was used the primary fibroblast (PF) culture of Fisher rats. In IF, the collagenase activity was at the same level as it was in PF. The activity of uPA in IF was increased by 2-2.5-fold; the titrated amount of free endogenous inhibitors in IF and PF was at essentially the same level while being markedly higher than in TF. At the stage of fibroblast transformation with the E7 gene of HPV-16, there was seen an increase of Type IV collagenases and a decrease of Type I collagenase, both these indices being most pronounced in the cells with most developed tumorigenic properties. In TF there occurred a decrease of free endogenous MMP inhibitors relative to the enzyme activity and, at the same time, a decrease in uAF activity, indicating the changes occurring in the enzyme/inhibitor/activator ratio and hence the enhancement of the destructive potential of the cells (in this case, at the cost of Type IV collagenase activity).

[Limited proteolysis of integrin alpha v beta3 from human placenta]. / Ogranichennyi proteoliz integrina alpha v beta3 iz platsenty cheloveka.

Purification of alpha v beta 3 integrin from human placenta with successive usage of two affinity sorbents--immobilized monoclonal antibodies to alpha v beta 3 integrin and immobilized RGD-containing decapeptide allowed to purify this integrin's partially degraded fraction, that was nevertheless able to interact with its ligand. During the incubation of partially degraded alpha v beta 3 integrin at 37 degrees C its further degradation went on. Addition of serine proteinase inhibitors: (phenylmethilsulfonyl fluoride, leupeptin and aprotinin) completely suppressed integrin further degradation of alpha v beta 3. In preparations of intact and partially degraded alpha v beta 3 integrin specific activity of two serine proteinases--urokinase and dipeptidilpeptidase IV--was discovered. alpha v beta 3 integrin, undergoing limited proteolysis, had lesser affinity towards RGD peptide, that intact integrin. The results show, that alpha v beta 3 integrin from human placenta co-purifies with serine proteinases. It is suggested that a definite part of functionally active alpha v beta 3 integrin, extracted from human placenta by triton X-100, forms a stable complex with serine proteinases.

[Aminopeptidases in human leukemia cells]. / Aminopeptidazy v leikoznykh kletkakh cheloveka.

Aminopeptidase activity in lymphoid cells of patients with various lymphoproliferative diseases was studied. The enzyme activity was detected in lysates of all leukemic B- and T-cells. The lymphoid cells contained aminopeptidases of at least two classes: metallo- and SH-dependent enzymes. The SH-dependent aminopeptidase with pH optimum 8.5-9.0 was revealed in lymphoid cells for the first time, and it seems to belong to a poorly studied aminopeptidase family.

Proteolytic enzymes in human leukemic lymphoid cells. III. Aminopeptidases, angiotensin-converting enzyme, and its inhibitor in cells of different immunological phenotype.

Activities of plasma membrane proteinases such as angiotensin-converting enzyme (ACE), aminopeptidases, and dipeptidyl peptidase IV (DPP-IV) were determined in lymphoid cells of various immunological phenotype which were obtained from 30 patients with lymphoproliferative diseases. The enzyme activities significantly varied depending on the immunological phenotype and stage of cell differentiation, but no correlation was found between activities of ACE, DPP-IV, and aminopeptidases in the cells of different type. The cell lysates studied contained at least two classes of aminopeptidases: metal- and sulfhydryl-dependent enzymes. A sulfhydryl-dependent aminopeptidase with activity optimum at pH 8. 5-9.0 was found for the first time and is suggested to be from a poorly studied aminopeptidase family. In addition to ACE, lysates of leukemic T- and B-cells were found to contain an inhibitor of ACE which was not previously described for these cells.

[A comparative study of aspartyl and cysteine proteinases and their inhibitors in human B- and T-cell leukemias]. / Sravnitel'noe izuchenie aspartil'nykh, tsisteinovykh porteinaz i ikh ingibitorov v leikoznykh B- i T-limfotsitakh cheloveka.

A procedure was developed for simultaneous isolation of aspartyl and cysteine proteinases as well as of the cysteine-proteinase inhibitors. Affinity chromatography using pepstatin-Sepharose enabled one to isolate aspartyl proteinases, while inhibitors of cysteine-proteinases were isolated by affinity chromatography on CM-papain-Sepharose; further purification of the enzymes was carried out using ion exchange chromatography and gel filtration. Partially purified preparations of cathepsin D as well as of cysteine-proteinases and their inhibitors were obtained. Some physicochemical and enzymatic properties of the enzymes and inhibitors obtained were studied.