ri ▁from ▁those ▁in ▁superior ▁temporal ▁gy ri ▁in ▁human ▁brain ▁t issue . ▁Both ▁of ▁them ▁are ▁being ▁research ed ▁in ▁relation ▁to ▁Al z heimer ’ s ▁disease ▁( AD ) ▁and ▁all ▁three ▁ev oked ▁ 1 0 0 % ▁in hib ition ▁of ▁s perm ine - en hanced ▁[ 3 H ] M K - 8 0 1 ▁binding . ▁Con - G [ γ 7 K ] ▁and ▁Con - G [ S 1 6 Y ] ▁also ▁show ▁positive ▁results ▁in ▁morph ine ▁withdraw al . ▁ ▁Con - T - based ▁ ▁Con - T [ K 7 γ ] ▁is ▁a ▁synth etic ▁Con - T ▁pe pt ide , ▁where ▁the ▁ser ine ▁at ▁position ▁ 7 ▁is ▁replaced ▁with ▁Gla ▁resid ue . ▁Like ▁Con - G , ▁it ▁has ▁higher ▁aff inity ▁for ▁M g 2 + ▁than ▁for ▁Ca 2 + , ▁but ▁does ▁not ▁dim er ize ▁in ▁the ▁presence ▁of ▁M g 2 + . ▁ ▁Chem istry ▁ ▁Bio chem ically , ▁con ant ok ins ▁have ▁a ▁distinct ive ▁high ▁ γ - car box y gl ut am ate ▁content ▁and ▁low ▁c yst e ine ▁content . ▁Con ant ok ins ▁typically ▁lack ▁dis ulf ide ▁b onds , ▁in ▁contrast ▁to ▁most ▁families ▁of ▁con ot ox ins , ▁which ▁have ▁an ▁unus ually ▁high ▁density ▁of ▁dis ulf ide ▁cross - links . ▁ ▁The ▁in hib ition ▁of ▁N MD AR