Aminopeptidase in Bone Cells

Lipp, W

doi:10.1177/7.3.205

Cited by 47 publications

(17 citation statements)

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“…Numerous light microscope histochemical studies have demonstrated the following hydrolytic enzymes in bone cells : acid phosphatase (Burstone, I96O; Gibson & Fullmer, 1967;Handelman et al, 1964;Jeffree, i97 o;Schajowicz & Cabrini, 1964;Warner, x 964); 5'-nucleotidase (Gibson & Fullmer,I966); phosphoamidase (Schajowicz & Cabrini, I964); aminopeptidase (Lipp, 1959;Warner, I964); and/3-glucuronidase (Warner, 1964).…”

Section: Introductionmentioning

confidence: 99%

Electron microscopic localization of hydrolytic enzymes in osteoclasts

1972

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Synopsis.Acid glycerophosphatase activity (pH optimum, 5.o) has been found within osteoclasts by numerous workers but relatively few studies have been concerned with the neutral hydrolytic enzymes that have pH optima around 7.2. Evidence is presented in this paper to show that neutral enzyme activity can be demonstrated with p-nitrophenyl phosphate, ATP and p-chloranilidophosphonate as substrates. Activity against /3-glycerophosphate, inorganic trimetaphosphate or p-nitrocatachol sulphate as substrates was found to be limited to an acid pH range.Electron microscopic evidence indicated that many of the hydrolytic enzymes were present within single membrane-bound bodies, vacuoles, Golgi elements, and the agranular endoplasmic reticulum of the osteoclast. This reticulum was dilated to form large lysosomes. Such activity was distingly different from the function of the Golgi membrane in its formation of primary lysosomes.The relationships between lysosomes, cytoplasmic vacuoles, and extracellular release of enzyme through the specialized 'ruffled' border are shown and discussed.

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Section: Introductionmentioning

confidence: 99%

Electron microscopic localization of hydrolytic enzymes in osteoclasts

1972

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“…Wergedal (34) reported proteolytic activity at pH 8 in metaphyseal and diaphyseal bone. Leucine aminopeptidase (EC 3.4.11.2) was demonstrated in bone at pH 7 histochemically by Burstone (4) and Lipp (20) but they made no reference to epiphyseal cartilage. This enzyme was also found by Yea ger et al (36) and Johnson and Yeager (18) in periosteal cells and chondrocytes underlying surgically treated periosteum, in dental pulp by Oya et al (27), and in synovial membrane by Mitrovic (24).…”

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confidence: 99%

Naphthylamidase (Arylaminopeptidase) Activities in Rat Cartilages and Bone

Hirschman¹,

Hirschman²

1977

Enzyme

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Extracts of epiphyseal articular and costal cartilages and of metaphyseal bone showed different profiles of activity against 21 aminoacyl β-naphthylamides. Except for the activity against arginyl and lysyl j3-naphthylamides, most of the activities required the presence of Triton X-100 for extraction, suggesting that in situ, the enzymes are bound to or within membranous structures. Histochemical studies demonstrated that most, if not all, activity was intracellular. The activity is enhanced by Co^2+. TAME (2 X 10^-4 mol/1) inhibits activity against leucyl β-naphthylamide and some others, but has little, if any, inhibition of activity against alanyl β-naphthylamide. Gel filtration of the extract showed a high molecular weight active fraction eluting with proteoglycan, and an active fraction with an approximate molecular weight of about 230,000. Two active fractions are obtained by gradient elution from DEAE-cellulose.

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“…It was stated by Lipp | 1959] th at am inopeptidasc in bone parti cipates in the process of absorption and reconstruction of bony sub stance. As appears from the foregoing, leucine am inopeptidasc can react with m any types of protein.…”

Section: Resultsmentioning

confidence: 99%