Sequence and Features
- 10COMPATIBLE WITH RFC
- 12COMPATIBLE WITH RFC
- 21Illegal XhoI site found at 124
- 23COMPATIBLE WITH RFC
- 25COMPATIBLE WITH RFC
- 1000COMPATIBLE WITH RFC
This is a composite part for intracellular expression of PepACS. Panb1 is a constitutive promoter in yeast, which is expressed under anaerobic conditions, while under aerobic conditions, Panb1, as a repression target of ROX1, is inhibited. When Panb1 initiates the expression, PepACS is expressed and participates in the process of perming.
Usage and Biology
PepACS consists of several short peptides（PepA, PepC, SPB） with flexible GS-linkers. All these short peptides are coded by genes of keratin from human hair and related protein, which enables PepACS to interact with keratin. AAs seq of PepA: CCQSSCCKPSC AAs seq of PepC: PIYCPPTCYH AAs seq of SPB: LCRALIKRI PepA is hydrophobic (less than 10%). Polarity interactions, for example, could be formed due to reactional groups in its sequence, which enhance its specificity and oriental binding ability. Peptides rich in cysteine may form covalent bonds with keratin in the hair, while some of it could recombine or even break the disulfide bonds of keratin. Cysteine could binds to sulfydryl, which could apparently reduce the disulfide bonds in keratin. When electron receptors, e.g. oxygen dissolved in solution, are available, cysteine residue could form disulfide bonds with them, which are oxidized from the butyl of cysteine. The break down and reform of disulfide bonds is tightly related to the shape of the hair. Instead of alkaline and Sulphur containing relaxers, this peptide thought could be one brand new method of environmentally friendly control of hair shape.
Biologically speaking, human hair is one kind of complex fibers with various of shapes and components. The main ingredient of the hair is keratin, which is a bright structural protein, as a member of intermediate filament superfamily. According to calculation of amino acids constituent, 18% of keratin is cysteine. The hair filament is consisting of three main layers: cuticle, cortex and medulla. The medulla locates in the core area of the hair, which is partly or totally deficient in slender ones. The cortex is the main part of the hair, which consists of huge fiber of intermediate filaments. The helical α-keratin, major part of the intermediate filament, provides mechanic sustaining force. Single fiber in cortex cells is separated by membrane consists of KAPS, which is rich in cysteine but unclear of space structure. The supplementary fiber of keratin is entangled by iron force, hydrogen bonds, Van der Waal’s force and disulfide bonds. Wrapping outside of the cortex, the cuticle is consist of layers after layers of cells, constructing a kind of squama-like structure. Every cuticle cell has respective lower filaments layer, whose protein is entangled by cysteine.