Sudhakar K. Mallya

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Four new fluorogenic heptapeptide substrates have been synthesized with sequences that are optimized for five human matrix metalloproteinases (MMP). All four substrates are similar to one recently reported by Stack and Gray (1989, J. Biol. Chem. 264, 4277-4281) and have the fluorescent Trp residue in subsite P'2 and the dinitrophenol (DNP) quenching group(More)
The precise function of the yolk platelets of sea urchin embryos during early development is unknown. We have shown previously that the chemical composition of the yolk platelets remains unchanged in terms of phospholipid, triglyceride, hexose, sialic acid, RNA, and total protein content after fertilization and early development. However, the platelet is(More)
We have developed a sensitive and continuously recording fluorogenic assay for the thiol protease calpain. This assay uses the dipeptide substrate Suc-Leu-Tyr-4-Methoxy-2-Naphthylamine (Suc-LY-MNA) in Tris buffer (pH 7.5) in the presence of 0.1% CHAPS. The assay is linear over a wide range of enzyme concentration and is capable of detecting 10 picomolar(More)
Calf skin and rat tendon type I, bovine cartilage type II, and human amnion type III collagens have been radiolabeled by reaction with [3H]acetic anhydride, [3H]formaldehyde, and succinimidyl 2,3-[3H]propionate. All three reactions produce collagens with high specific activities that are suitable for use as substrates in collagenase assays. The identity of(More)
The mechanism of inhibition of two forms of human neutrophil collagenase (HNC) by six Au(I) compounds, some of which are used as chrysotherapeutic agents, has been investigated. The two forms of enzyme studied are active and latent HNC, the latter of which is activated by p-chloromercuribenzoate (PCMB). The effects of PCMB and Zn(II), which are normally(More)
The kinetics of hydrolysis of rat tendon type I, bovine nasal septum type II, and human placental type III collagens by class I and class II Clostridium histolyticum collagenases (CHC) have been investigated. To facilitate this study, radioassays developed previously for the hydrolysis of these [3H]acetylated collagens by tissue collagenases have been(More)
A series of experiments has been carried out to characterize 58-kDa human neutrophil collagenase (HNC) and compare it with human fibroblast collagenase (HFC). N-Terminal sequencing of latent and spontaneously activated HNC shows that it is a distinct collagenase that is homologous to HFC and other members of the matrix metalloproteinase gene family.(More)
Accurate and quantitative assays for the hydrolysis of soluble 3H-acetylated rat tendon type I, bovine cartilage type II, and human amnion type III collagens by both bacterial and tissue collagenases have been developed. The assays are carried out at any temperature in the 1-30 degrees C range in a single reaction tube and the progress of the reaction is(More)
Calpain I is a heterodimeric protein that is part of a family of calcium-activated intracellular cysteine proteases presumed to play a role in mediating signals transduced by calcium. Expression of bioactive recombinant human calpain I has been achieved using the baculovirus expression system, by either co-infection with two viruses, each expressing one of(More)