• 대한의생명과학회지
• /
• 제12권3호
• /
• pp.185-190
• /
• 2006

Lysyl oxidase (LOX) catalyzes the lysine-derived cross-links of fibrillar collagens and elastin in the extracellular matrix. Recent molecular cloning has revealed existence of a LOX family consisting of LOX and four lysyl oxidase-like proteins (LOXL, LOXL2, LOXL3 and LOXL4). Pathological conditions associated with impaired LOX activity in several heritable and acquired disorders lead to severe structural and functional abnormalities of cardiovascular tissues, such as occlusion of coronary arteries and aneurysms, suggesting an essential role for the LOX family proteins in the maintenance of the cardiovascular system. However, the specific roles of the lysyl oxidase-like proteins in normal and pathological conditions of the cardiovascular tissues have not been established yet. Here, I report that LOXL3, a novel member of the LOX family, is predominantly expressed in the aorta, with an amine oxidase activity toward collagen and elastin, suggesting an essential role of LOXL3 in the development and maintenance of the aorta.

• 생명과학회지
• /
• 제14권3호
• /
• pp.478-483
• /
• 2004

AsA 및 그 관련화합물, 각종 환원제 등을 첨가하여 lysine의 산화반응에 미치는 영향에 대하여 검토하였다. AsA의 첨가에 의해 lysyl oxidase활성의 지표인 과산화수소의 생성량은 대조군에 비하여 감소하였다. 2 $\mu$M의 AsA의 첨가에 의해 효소활성은 완전히 억제되었고, 0.2 $\mu$M 농도에서 억제효과가 나타났으나 40분 경과 후 다시 활성이 상승하는 경향이 나타났다. 또한 0.02$\mu$M 에서는 효소활성 의 변화는 대조군과 비슷한 경향을 나타내었다. 효소활성은 환원형 AsA에서 저해 효과가 높았으나 산화형 비타민 C (dehydroascorbic acid: DHA)와 환원제인 glutathione (GSH)에서는 억제효과가 크게 나타나지 않았다. AsA의 입체이성체인 ErA는 AsA와 같이 lysine 산화반응에서 억제적으로 작용하고 환원제인 GSH 보다도 lysyl oxidase에 미치는 영향은 큰 것으로 나타났다. 즉, lysine산화반응에 미치는 억제 효과는 환원제로서는 AsA와 ErA에서만 나타났으므로, 그 구조가 lysyl oxidase에 관여 할 가능성이 보여졌으므로, AsA의 analogue인 3,4-dihydro-xybenzoate를 이용하여 lysyl oxidase의 효소활성에 미치는 영향을 검토하였다. AsA의 analogue인 3,4-dihydroxyben-zoate를 첨가하였을 때에도 lysyl oxidase 활성은 억제되어, AsA의 analogue가 AsA와 같은 효과를 나타내었으므로 AsA의 endiol기의 작용 가능성을 추측할 수 있다. 이러한 결과로부터 lysine의 산화반응은 AsA에 의해 억제되고, 그 억제 효과는 AsA의 endiol기가 효소-구리이온 복합체를 환원할 때 효소의 활성부위에 접근하여 나타나는 것으로 사료된다.

• Journal of Oral Medicine and Pain
• /
• 제25권1호
• /
• pp.29-39
• /
• 2000

소(牛) 태아 대동맥으로 부터 Urea 추출, Sephacryl S200 HR 크로마토그라피, Cibacron blue-agarose 친화 크로마토그라피, 그리고 Sephacryl S300 HR 크로마토그라피를 이용하여 lysyl oxidase를 순수분리를 하였고 분리가간 중 항상 단백분해 억제제를 첨가하였다. 순수 분리된 효소는 가교결합이 없는 교원단백질과 엘라스틴에 활성을 보였고, BAPN 같은 아미노나이트릴에 의하여 억제되였다. Sephacryl S300 HR 크로마토그라피로 분리 될 경우, 이 효소는 0.45의 $K_{av}$ ($V_t$의 65%)값을 보였고, 이온교환 고속액체 크로마토그라피의 경우에서는 이온 강도가 0.1-0.15 사이에서 하나의 피크로 용리되었다. 순수 분리된 이 효소는 SDS 폴리아크릴아마이드 전기영동에서는 하나의 밴드로 이동하였는데, 환원이 될 경우에는 분자량이 33,500, 비환원이 될 경우에는 분자량이 24,500의 위치로 이동하였다. 이온교환 고속액체 크로마토그라피의 결과를 참조하여, 다른 보고서와는 달리 소(牛) 태아(服兒) 대동맥(大動服)에는 여러 종류가 아닌 한 종류의 lysyl oxidase가 존재한다고 결론을 내렸다.

• 한국식품영양과학회지
• /
• 제27권2호
• /
• pp.305-312
• /
• 1998

Normal tensile strength in collagen fibrils is due to intermolecular and intramolecular crosslinks which are known to be altered in aging. Pyridinoline, a mature crosslink which is stable and nonreducible, is derived from two hydroxyallysine and one hydroxylysine residues of collagen fibrils. The excess formation of pyridinoline in collagen is associated with making the tissue stiffer, less soluble and less digestible by enzymes. Lysyl oxidase is the enzyme that initiates the biosynthesis or crosslinks in collagen by catalyzing the oxidative deamination of the lysyl and hydroxylysyl residues in these molecules, and its activity is inhibited by $\beta$-aminopropionitrile(BAPN). Our previous work demonstrated that the pyridinoline content of bone collagen significantly was increased during incubation for 5 weeks at 37$^{\circ}C$ invitro, but it was diecrased by the addition of ascorbic acdi(AsA). In this study, we clarified the specific action of AsA in aging process in vitro enzymatic reaction.

• 한국식품영양과학회지
• /
• 제26권3호
• /
• pp.475-479
• /
• 1997

A decrease in the circulating levels of estrogen, occuring as a consequence of post menopausal decline or from surgical ovariectomy, results in an accelerated loss of bone. Estrogen has been shown to stimulate lysyl oxidase activity, and the treatment with estrogen increased the pyridinium content of cortical bone. a trivalent mature cross-links collagen fibrils named pyridinoline, which is especially abundant in collagen of cartilage and bone, markedly increases with growth in humans and rats. The main aim of this study was to examine the increased bone loss caused by ovariectomy through monitoring the concentrations of the collagen and the pyridinium cross-links of collagen, pyridinoline. The ovariectomized rats, 4 weeks old, were divided at random into two or three groups of 5. Ovariectomies were carried out on both of the saline-treated group(OVX(NH)) and the estrogen-treated group(OVX(H)) using the dorsal approach and sham operations were performed on the sham-operated group(sham). They were maintained under identical conditions for 4 or 8 weeks and were allowed free access to food and water. it was observed that there was no significant difference between the control group and the sham-operated group, however, the control group had a higher content of collagen than the saline-treated group after 4 weeks and 8 weeks. Based on these results, iot is supposed that estrogen can enhance collagen synthesis and affects the pyridinoline formation in collagen fibrils through stimulating lysyl oxidase activity.

• 치위생과학회지
• /
• 제13권3호
• /
• pp.296-303
• /
• 2013

LOX는 결합조직의 세포외기질에 존재하여 교원섬유와 탄성섬유의 교차결합을 촉진시키는 핵심적인 효소이다. 뼈세포에서 세포분화 및 세포이동과 관련된 LOX의 역할은 보고되었으나, 상아모세포 분화에서 LOX에 대한 직접적인 효과는 거의 알려지지 않았다. 이 연구에서는 인간치수세포에서 상아모세의 분화과정 동안 LOX의 역할에 대해 실험하였다. 치수세포에 저 혈청 분화유도 배지를 처리하여 0, 1, 3, 7, 14일 동안 배양하였다. 세포성장은 세포계수, 분화와 관련된 유전자들은 RT-PCR, 광물화는 alrizarin red S 염색으로 각각 실험하였다. LOX 유전자 발현은 RT-PCR로 측정하였고, LOX 효소활성은 고감도 형광분석을 시행하였다. 1. 세포성장은 저 혈청 분화유도 배지에서 시간 의존적으로 증가하였다. 2. 분화표지자인 ALP, OPN, OCN, DMP1, DSPP는 시간 의존적으로 발현되었으나 초기, 중기, 말기에 대한 차별화는 이루어지지 않았다. 3. 광물화는 3일부터 관찰되기 시작하여 14일까지 증가되었다. 4. LOX와 LOXL은 mRNA 발현이 7일까지 증가되었고, 14일에서 큰 감소를 보였다. 하지만, LOXL3와 LOXL4 mRNA는 낮은 발현을 보였고, LOXL2 mRNA는 발현되지않았다. 5. Collagen type I mRNA는 7일까지 증가하다가 14일에서 의미있게 감소를 보였고, collagen type IV는 낮은 mRNA 발현을 보였다. 6. LOX 효소 활성은 분화유도기간 중 7일에서 가장 많은 발현을 보였고, 교원질 1형 기질이 교원질 IV형 기질보다 두드러진 발현을 보였다. 이상의 결과를 종합해 볼 때, LOX isoform의 발현과 LOX 효소 활성은 인간치수세포에서 상아모세포 분화과정 동안 중요한 조절자로 사료된다.

• 치위생과학회지
• /
• 제13권3호
• /
• pp.321-329
• /
• 2013

과산화수소는 치아미백에 널리 사용되는 물질로 과다 사용시 치수세포에 손상을 일으킬 수 있다. 본 연구의 목적은 활성산소인 과산화수소에 의해 유도되는 상아모세포의 단계별 분화와 LOX isoforms과의 관계를 밝히고자 하였다. 치수세포에 분화유도 배지와 과산화수소를 시간과 농도별로 처리한 후 LOX 유전자 발현은 RT-PCR로 측정하였고, LOX enzyme activity는 고감도 형광분석으로 확인하였다. 또한 가장 많은 발현억제를 보인 LOX와 LOXL을 선택하여 siRNA 처리 후 분화표지자의 발현변화와 LOX enzyme activity를 확인하였다. 1. 과산화수소 처리에 따라 LOX, LOXL, LOXL3 mRNA 발현은 농도와 시간 의존적으로 감소하였으나 LOXL2와 LOXL4 mRNA는 변화가 없었다. 2. 과산화수소 처리된 LOX enzyme activity는 0.3 mM과 24시간에서 가장 많은 증가를 보였다. 3. ALP, OPN, OCN의 mRNA 발현은 LOX와 LOXL siRNAs 모두에서 억제되었고, DMP1과 DSPP는 LOX siRNA에서 더 많은 억제 효과를 보였다. 하지만, 분화단계별(초기, 중기, 말기) 차이는 보이지 않았다. 4. LOX와 LOXL siRNAs를 처리하여 LOX enzyme activity를 측정한 결과 LOX siRNA를 처리한 실험군에서 더 많은 억제효과를 보였다. 이러한 결과는 상아모세포 성장과 분화과정에 낮은 농도의 과산화수소가 분화를 유도하고 여기에 LOX가 관련됨을 알 수 있었다. 결론적으로, 과산화수소는 LOX 유전자 발현조절을 통해 치수세포의 성장과 분화에서 중추적인 역할을 할 것이라고 생각된다.

• BMB Reports
• /
• 제29권4호
• /
• pp.321-326
• /
• 1996

Spinach glycolate oxidase was subjected to a series of chemical modifications aimed at identifying amino acid residues essential for catalytic activity. The oxidase was reversibly inactivated by treatment with pyridoxal 5'-phosphate (PLP). The inactivation by PLP was accompanied by the appearance of an absorption peak of around 430 nm, which was shifted to 325 nm upon reduction with $NaBH_4$. After reduction, the PLP-treated oxidase showed a fluorescence spectrum with a maximum of around 395 nm by exciting at 325 nm. The substrate-competitive inhibitors oxalate and oxaloacetate provided protection against inactivation of the oxidase by PLP. These results suggest that PLP inactivates the enzyme by fonning a Schiff base with lysyl residue(s) at an active site of the oxidase. The enzyme was also inactivated by tryptophan-specific reagent N-bromosuccinimide (NBS). However, competitive inhibitors oxalate and oxaloacetate could not protect the oxidase significantly against inactivation of the enzyme by NBS. The results implicate that the inactivation of the oxidase by NBS is not directly related to modification of the tryptophanyl residue at an active site of the enzyme. Treatments of the oxidase with cysteine-specific reagents iodoacetate, silver nitrate, and 5,5'-dithiobis-2-nitrobenzoic acid did not affect significantly the activity of the enzyme.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권6호
• /
• pp.3613-3618
• /
• 2013

Object: To detect expression of hypoxia inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) and lysyl oxidase (LOX) in non-small cell lung cancer (NSCLC) and explore their roles in prognosis. Methods: The mRNA levels of HIF-$1{\alpha}$ and LOX were investigated by real-time reverse-transcriptase polymerase chain reaction in 40 cases of tumour and paired normal tissues. In addition, protein expression of HIF-$1{\alpha}$ and LOX was examined by immunohistochemistry in 82 cases of tumour and 45 paired normal tissues. The relationship between HIF-$1{\alpha}$ or LOX and clinicopathologic characteristics, as well as the correlation between HIF-$1{\alpha}$ and LOX, were also examined. Kaplan-Meier survival curves and the log-rank test were used to analyze progression-free survival. Results: HIF-$1{\alpha}$ or LOX mRNA levels in tumor tissues was significantly higher than those in paired normal tissues (p<0.01). Positive HIF-$1{\alpha}$ or LOX protein expression in tumor tissues was noted in 46/82 (56.1%) and 49/82 (59.8%) of the cases, respectively, being significantly higher than those in paired normal tissues (p<0.05). There was significant correlation between the expression of HIF-$1{\alpha}$ or LOX and tumor size, lymph node metastasis and pathological stage (p<0.05). The expression of HIF-$1{\alpha}$ and LOX had a significant inverse impact on survival of patients with NSCLC. Conclusion: HIF-$1{\alpha}$ and LOX may play a pivotal role in the development of NSCLC, and may act in synergy to promote the progression of NSCLC.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권6호
• /
• pp.3805-3808
• /
• 2013

Background: Osteosarcomas have many established risk factors, both genetic and environmental, but by themselves these explain only part of the total cancer incidence. Bisphenol A (BPA) is an environmental estrogen associated with risk of several kinds of tumour. The lysyl oxidase gene (LOX) may also contribute to risk of tumours including osteosarcomas. Here, we investigated possible interactions of BPA and a LOX polymorphism on the risk of osteosarcoma. Method: The present hospital-based case-control study included 106 cancer patients and 112 controls from a Chinese population. Internal burden of BPA exposure was assessed using high-performance liquid chromatography-mass spectrometry (HPLC-MS) method. Genotypes were determined using PCR-RFLP methods. Results: Compared with those in low BPA exposure group, subjects with BPA more than or equal to median value had significant increased risk of osteosarcoma among subjects who carried GC or CC genotypes. A significant interaction with BPA level and the -22G/C polymorphism was observed for osteosarcoma overall, osteosarcoma affecting knee and osteosarcoma affecting hip, as $P_{forinteraction}$ = 0.036 for osteosarcoma overall; $P_{forinteraction}$ = 0.024 for osteosarcoma affecting knee; and $P_{forinteraction}$ = 0.017 for osteosarcoma affecting hip. Conclusions: The results suggest that BPA exposure interacts with the -22G/C polymorphism of the LOX gene to increase the risk of osteosarcoma.