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Table 2 Tandem electrospray-mass spectroscopy identification of phospholipids associated with connexin channels – PC.

From: Connexin channels and phospholipids: association and modulation

amu observed amu expected PC
(a) i – Cx26 unique, hemichannels
   None
(b) i – Cx26 unique, plaques
480.32 480.34 16:0e lyso
766.64 766.57 36:5e or 36:4p
768.64 768.59 36:4e or 36:3p
802.72 802.66 38:1e or 38:0p
846.64 846.69
846.63
40:0
42:6p
(a) ii – Cx32 unique, hemichannels
520.30 520.34 18:2 lyso
(b) ii – Cx32 unique, plaques
544.24 544.34 20:4 lyso
(a) iii – common to Cx26 and Cx32, hemichannels
706.50ϕ 706.53 30:0
784.50 784.58 36:3
790.70 790.63 36:0
808.50ϕ 808.58 38:5
812.60 812.61 38:3
816.60 816.64 38:1
894.70 894.69 44:4
(b) iii – common to Cx26 and Cx32, plaques
706.50ϕ 706.53 30:0
808.50ϕ 808.58 38:5
  1. PC phospholipids in (a) hemichannel-detergent micelles and in (b) junctional plaques containing (i) only Cx26, (ii) only Cx32, or (iii) that are in both Cx26 and Cx32 samples, after removal of phospholipids found in negative control samples that did not contain either connexin. Tables are collated by unique mass (amu), with tolerance ± 0.10 amu from expected. Species highlighted with ϕ are found in both isolated plaques and hemichannel preparations containing the same connexin isoform. PC = phosphatidylcholine; e = alkyl ether glycerol-alkyl chain linkage; p = plasmenyl glycerol-alkyl chain linkage; lyso = lysophospholipid. Absence of e or p denotation indicates conventional ester glycerol-alkyl chain linkage. n equals two to seven tandem electrospray-mass spectroscopy runs per sample.