For the purposes of this article, the term "security trust" shall include a deed of trust, mortgage, bond or other instrument, entered into after the effective date of this article under which the title to real and personal property, or either of them, wholly situate in and including no property situate outside of the State of West Virginia, is conveyed, transferred, encumbered or pledged to secure the payment of money or the performance of an obligation: Provided, however, That the provisions of this article shall not apply to supplements to existing security trust instruments now of record executed pursuant to the provisions of said existing security trust instruments.