Acetylcholinesterase from the Skeletal Muscle of the Lamprey Petromyzon marinus Exists in Globular and Asymmetric Forms

Abstract

To obtain information about the evolution of acetylcholinesterase (AChE), we undertook a study of the enzyme from the skeletal muscle of the lamprey Petromyzon marinus, a primitive vertebrate. We found that the cholinesterase activity of lamprey muscle is due to AChE, not pseudocholinesterase; the enzyme was inhibited by 1,5-bis(4-allyldimethylammonium phenyl) pentane-3-one (BW284C51), but not by tetramonoisopropyl pyrophosphortetramide (iso-OMPA) or ethopropazine. Also, the enzyme had a high affinity for acetylthiocholine and was inhibited by high concentrations of substrate. A large fraction of the AChE was found to be glycoprotein, since it was precipitated by concanavalin A-agarose. Optimal extraction of AChE was obtained in a high-salt detergent-containing buffer; fractional amounts of enzyme were extracted in buffers lacking salt and/or detergent. These data suggest that globular and asymmetric forms of AChE are present. On sucrose gradients, enzyme that was extracted in high-salt detergent-containing buffer sedimented as a broad peak of activity corresponding to G4; additionally, there was usually a peak corresponding to A12. Sequential extraction of AChE in conjunction with velocity sedimentation resolved minor forms of AChE and revealed that the G1, G2, G4, A4, A8, and A12 forms of AChE could be obtained from the muscle. The identity of the forms was confirmed through high-salt precipitation and collagenase digestion. The asymmetric forms of AChE were precipitated in low ionic strength buffer, and their sedimentation coefficients were shifted to higher values by collagenase digestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Evolution of Acetylcholinesterase and Butyrylcholinesterase in the Vertebrates: An Atypical Butyrylcholinesterase from the Medaka Oryzias latipes

“…Although a number of cDNAs have been cloned for AChEs from these organisms, molecular information about the atypical BChEs present is unavailable. Moreover, only a single ChE, AChE, has been identified functionally and molecularly in the jawless fish, the lamprey Petromyzon marinus [23] and the hagfish Myxine glutinosa [24]. These observations suggest that AChE is the ancestral ChE in the vertebrates and that an early gene duplication event and subsequent divergent structural and functional evolution produced the AChE and BChE of higher vertebrates [23], [25].…”

Surface material recognition through haptic exploration using an intelligent contact sensing finger

“…Methods have been proposed to identify the object global or local geometry properties through tactile sensing. Using tactile array sensors to classify the shape of the object through the analysis of the tactile images have been introduced in [6,7]. In [8,9], a series of haptic exploration strategies have been proposed to recognize the shape of an unknown object and to detect small surface features, such as cracks, bumps, and ridges using a robotic hand.…”

“…To date, various approaches have been proposed to identify object surface properties through haptic feedback [5][6][7][8][9][10][11]. Methods have been proposed to identify the object global or local geometry properties through tactile sensing.…”

Molecular characterization of an acetylcholinesterase from the hemichordate Saccoglossus kowalevskii

“…Conventional thinking is that AChE is the ancestral ChE in the craniates, and that BChE resulted from a gene duplication event early in vertebrate evolution, with subsequent structural and functional divergence in the acyl pocket and other catalytic subsites (Chatonnet and Lockridge, 1989;Pezzementi et al, 2012). Supporting this view is the apparent presence of only AChE in the invertebrate craniates, the hagfish and the lamprey (Pezzementi et al, 1987;Sanders et al, 1996), and the presence of atypical BChEs with characteristics intermediate to AChE and BChE in various cartilaginous and bony fish (Lundin, 1968;Toutant et al, 1985;Leibel, 1988a,b;Stieger et al, 1989;Pezzementi et al, 2012). However, the presence of a BChE-like acyl pocket in a putative BChE from the cartilaginous fish Callorhinchus milii, and an acyl pocket resembling either the protostome pocket or a pocket intermediate to craniate AChE and BChE in the atypical BChE of the bony fish Oryzias latipes (Pezzementi et al, 2012), potentially confounds this interpretation.…”