1. Yeast alcohol dehydrogenase inactivated by reaction with iodoacetamide retains 85% of the original NADH-binding capacity as measured under conditions of saturating coenzyme concentration. 2. The dissociation constant of the enzyme-NADH complex is unaffected by inactivation of the enzyme with iodoacetamide, and the affinity of the enzyme for NAD(+) and pyridine-3-aldehyde-adenine dinucleotide...

A chiral cyclophane–type macrocycle bearing two thiol groups has been prepared by chemical modification of S,S-(+)-tetrandrine. Cleavage of p-nitrophenyl acetate by deprotonated form of this macrocycle proceeds with a rate constant expected for a simple thiol anion of similar basicity, but the reactivity toward p-nitrophenyl esters of N-protected amino acids is one order of magnitude higher tha...

1. Considerable differences were found between the rates and degrees of modification of native trout actin with iodo[2-(14)C]acetate and iodo[1-(14)C]acetamide. 2. With iodoacetate, G- and F-actin were both labelled in the N-terminal peptide only. This modification had little effect on the ability of the actin to polymerize. 3. Iodoacetamide labelled three cysteine residues in both G- and F-act...

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When the SH groups of various derivatives of human haemoglobin are converted into their mercuric mercaptides small changes are observed in the optical rotatory dispersion in the range 385-294mmu. These changes are proportionately greater for the reactive than for the unreactive SH groups. These observations have been interpreted in terms of the conformational changes that are likely to occur in...

Bioconjugation based on crosslinking primary amines to carboxylic acid groups has found broad applications in protein modification, drug development, and nanomaterial functionalization. However, proteins, which are made up of amino acids, typically give nonselective bioconjugation when using primary amine-based crosslinking. In order to control protein orientation and activity after conjugation...

Thiol-bearing microgels have been synthesised from copolymerisation of 2-(acetylthio)ethylacrylate and 2-hydroxyethylmethacrylate, and subsequent deprotection using sodium thiomethoxide. The concentration of thiol groups on these microgels could be tailored by use of different molar ratios of the two monomers. These thiol-bearing microgels were shown to adhere to ex vivo porcine urinary bladder...

unable to bind NADPH. The results obtained so far suggest that the modified histidine residue is in, or near, the coenzyme site, and the protection by inhibitors competitive with NADPH suggest that it is in the region of the binding site for adenosine ribose and distal to the site of hydride transfer. Thiol groups. The role of thiol groups in the activity of mammalian aldehyde reductases is not...

Background: There are several causes leading to male infertility, like oxidative stress, and nutritional deficiency of trace elements i.e., selenium and zinc. The Zinc is the following only to iron as the most abundant element in the body. Although, Zinc is found in red meat, white meat, fish, and milk; the World Health Organization (WHO) approximates that one-third of world population is defic...

Introduction: Toxic effects of pesticides are commonly associated with reactive oxygen species damage and pentoxifylline a phosphodiesterase inhibitor is a drug well known for antioxidant properties. The purpose of this study was to evaluate the oxidative damages following a subacute exposure to malathion, an organophosphorus insecticide and pentoxifylline's ability to counteract these effect...